When I took a bunch of rolled change to the bank, they wanted my name and address on each roll…
I’ve gotten some pretty nice ones. I use them as long as they’re from an organization I think is OK; it’s not like anyone else is going to have a use for them.
They’re never from charities that I actually donate to (I have problems with the concept of giving donors presents, but that’s another thread). No guilt here.
I generally use about a dozen of the labels and then lose them. If they’re from an organization that I support and I have the money, I’ll send money; if they’re from an organization I oppose, I don’t send anything, and don’t feel guilty.
All I had to do was to donate to ONE of them and now I get labels from a handful of different organizations. The ones I get aren’t tacky at all. I mean, seriously, how much do you analyze the return address when you’re getting mail. I’m just tickled that someone thought enough of me to sit down and <gasp> write a letter!
Hopefully it’s not Volvo Donor~
I use any little gifts that come in the mail completely guilt-free. They were an unsolicited incentive; it seems ridiculous to throw them out based on whether or not I give financial support to the organization (Note: I’ve yet to receive any of this type of thing from an organization I don’t support in theory). Thus far in my life, this has included not only return address labels, but also notecards, gift labels, calendars, and, most recently, wrapping paper.
Of all the organizations that have sent such stuff, I’ve only given money to one, and that decision wasn’t based on the mailing.
Use them, throw them out, do what you will. I work for a charity, and we get those disgustingly cheap since we mass-order them. Just don’t feel guilty!
We get them from a lot of different groups because we donate to the ASPCA and the American Cancer Society. We pretty much us all of them except for the ones we got from PETA. I tore those up and threw 'em in the garbage.
I got a bunch right after I moved – which was really handy – and have been using them guilt-free on various forms of correspondence. Mostly bills, but some of them get put on actual letters, like the ones from VFW that have the American flag on them. Those are actually kinda cool. The Salvation Army ones aren’t bad, either, because most of them have no logo at all.
Unfortunately, I’m just about to run out of the free labels. 
I have two Salvation Army ones left, and three from VFW. And I don’t get it, because I actually donated to one or two of the charities that sent me labels (like Special Olympics, who now only sends me soliciation letters with that square “I donated this year” sticker).
I guess I’ll just have to break out my ink jet labels . . . or maybe I’ll order some fancy labels from one of those “we’ll send you 2000 return address labels for $2!” places. 
I keep them if I like the design and if they’ve spelled my name right (I’ve gotten a lot that have my middle initial bizarrely welded onto my last name – Miss Lmapp?) Otherwise, they get thrown out. If it’s a charity I’d give money to anyway, I’ll do so – but then I’ve given money to charities that never send me anything.
I get so many of them that even though I throw out any that don’t get my name and address perfect and even though I use about 200 of them a year, I still have accumulated a pile of about 600 to 800 of them.
I use 'em if they don’t have the charity label on 'em. Wooohoooo, free stuff!
I use 'em and don’t feel guilty. I didn’t ask for them to send them to me, they sent them on their own.
I use them and usually send in a few bucks. They’re worth it to me, and they’re always from an organization I support anyway.