I’m not talking dainty wallet sized purses, but the kind that holds everything PLUS a good book.
Do you:
Take it with you into meetings?
Leave it under your desk, hoping no-one will notice it?
Leave it at home?
Lock it in your desk and take the key with you, only to forget it somewhere?
I usually leave it under my desk in the corner, but if I’m leaving my desk for a while, I’ll lock it up in my desk, which has a numeric lock, rather than a key lock.
I put it in a cabinet, out of sight but not locked.
I don’t have one as big as you describe. I have a small purse (smaller than an American football), which I put in a desk drawer. The drawer isn’t lockable, but I don’t feel concern that anyone would take it. We don’t really have meetings here, per se - sometimes we’ll all gather together to discuss something for a few moments, but it’s a small office, so I could see anyone try to walk into my office from the “common” area.
I also have a larger bag, which I bring my food in (breakfast, lunch, beverages) - it’s insulated, but it looks much like a large purse or tote bag. It also has a pocket for reading materials, and an umbrella holder. I just leave it sitting behind my desk. It doesn’t contain valuables.
I leave it in my office strewn about somewhere under the coatrack. I don’t even lock the door if I go out because this part of the building is federal and you need a key card to even get into the department.
In a drawer out of sight. If I’m away from my desk, I usually lock the drawer. But then I just throw the keys in another drawer, so I doubt I’m really adding much security.
We have limited access to my floor, so it’s not like unknown people are wandering about.
We’ve each got a locker/file cabinet combo unit in our cubes, and my purse and lunch cooler go in there. Sometimes I forget and leave it in the corner of my work area by the locker. But I work in a very secure building with a bunch of folks with nice, high security clearances. If I can’t trust them, who can I trust?
I leave mine in an unlocked desk drawer. It’s rare that everyone will be gone from our department, so there’s no fear of strangers wandering around unsupervised. If we’re all going to be in a meeting for a while, I’ll shut and lock my door.
Unlocked bin in my cubicle – out of immediate sight but not inaccessible. Our office doesn’t have a lot of strangers wandering around, so I don’t really worry about it.
Strangely I was just talking about this with my co-worker. She got two credit cards swiped from her purse while she was working. It was done by two women who made a career of walking into businesses wearing professional attire and swiping what they could as quickly as they could. Key is that they didn’t take the purse, but a credit card or two, which wouldn’t be immediately missed. When they were caught, months later, they said they’d look in the bottom right hand drawer as surreptitiously as they could because most women keep their purse there.
So, my answer to this is to lock it up or, at the very least, put it a left hand drawer.
I never know what to do with my purse. The whole point of having a purse is not having to carry cumbersome loose keys, wallets etc around. After a while of purse-carrying, I kinda forget how to carry all that loose stuff around. It just doesn’t feel right anymore to bring loose keys, wallets etc with you into a meeting and put them in front of you.
So, in spite of office-security tips like this one, I do as all posters; leave my purse stuffed away in a right hand (!) drawer. If I lock it, I put the keys in another unlocked drawer.
I also have a " decoy" bag with not-so-urgent reports to read at home. I leave that one in full view, hoping a thief will get that one and have nothing to show for his efforts but a few boring reports.
I work in a public building with a staffed desk. The women at the desk will stop anyone obviously looking like a junkie. But they can’t keep every one out.
But every two years or so, there will be a bout of thieving going on in the building. I always wondered what kind of thief was the culprit. The thief would steal money, but he would also steal ugly little statuettes on desks. 
I envisioned professional looking female thieves like the ones in PunditLisa’s story could pull off thieving bouts like that. Strange to see such criminals exist in reality as well.
My mom once had her wallet stolen form her purse at the office. She suspected an innocent co-worker, and it poisoned office relations for quite some time, before her wallet was found in a gutter somewhere and some arrested junkie confessed to having robbed that particular office. My mom never apologized to her co-worker, be I’m sure he was glad she stopped the inexplicable hostile glares at him.
I lock my bag/purse up in my desk. Not in a drawer but rather a “coat locker” thing attached to the cube (and whoever designed it never had to deal with real winter boots and a Chicago-weight coat!). Like I said - it’s locked, and the key comes with me. Either in my pocket or on a cord around my neck so I don’t lose it.
I leave it tucked way under my desk, as I don’t have room for it in any of my drawers.
My office is in a high rise, with fairly tight security, but we still have our yearly rash of wallet and purse thefts. Given that you have to get past security in the lobby, who’ll only let you in if you’re on the approved list, and you need a building pass to access anything outside the elevator banks, I see no reason to assume that the thieves don’t work in or for the building. It’s *possible * that they don’t, of course, but it seems less likely.
That said, the story of those two women doesn’t surprise me at all. Although you can’t just walk into our offices without a pass, if you look “right”, someone will eventually come along and hold the door for you.
I carry a messenger bag, which I tuck under my desk. I don’t really leave it there unsupervised for long periods of time, and have never had a problem. I also sit by the door and see who is coming and going all day.
Also: my building as a regional FBI office on the floor below my office, so we have unusually good security.
That is exactly where I have my purse. Fortunately, we have a secure building so I don’t think I have to worry about having anything stolen.
I keep mine in an unlocked drawer. My desk is in an area of fairly high traffic, but the traffic consists of co-workers, not the general rabble. 
It’s not that I have such great faith in the honesty of my co-workers, but I think it would be difficult for any one of them to go rummaging in my desk without another one coming by and catching them. I’ve been lucky so far.
Mine sits under my desk. It used to go in an unused file drawer, but now that drawer has files in it! I work in a tiny office with three guys. The building is much larger, but our door to the hallway is always locked.
I have an office. It stays under my desk during the day; if I go out, it goes with me.
VCNJ~
Right now, it’s sitting on my desk to the left of me. Usually, it’s there, or on my credenza behind me, or it’s on the chair in my cube. Keycard building and I trust my co-workers. Plus, I sit all the way in the back corner of our area, and I never have any money anyway. Or credit cards. All a thief would get would be some overdue Martha Stewart bills, my marriage certificate, and other assorted bullshit.
No purse here. My keys (attached to a little wallet thingie) stay in my coat pocket on the back of the door, or just on the desk. It’s relatively safe and out-of-the-way here.