My wife and I love to tour wineries. We’ve been to 48 states (no lie!) and did tastings in many of them.
We were in the Frisco area summer of '05, but were on a schedule so we only got to spend 1 day in Napa.
We’ve decided to go back down this coming summer and spend at least 4 days in wine country.
Can anyone give me heads up on wineries that don’t charge (or charge very little) for tasting? We’d like to add it to our list of places.
There are going to be more wineries that don’t charge for tasting somewhere like Healdsburg than there are in a well-known part of wine country like Napa Valley. They’ve got a good tourist business going, and they know it.
You’d also have better luck finding a place that won’t charge in the off-season than you will in the summer, particularly on weekends in the summer.
Do you usually buy wine at the wineries? A lot of places waive the tasting fee if you do.
Oh, and don’t call it “Frisco” while you’re here- the ghost of Emperor Norton might decide to screw up traffic where you’re going if you do… 
More and more wineries in both Napa and Sonoma Counties are charging tasting fees. It might still be a little easier to find wineries that don’t charge for tastings in Sonoma than Napa, but not much. (Here’s a fairly recent article on the subject.)
Best I could find was a list on a blog from 2003 of wineries that offered free tastings then - here, but I’d guess that more than a few of them are now charging. The trend to charge for tastings has really grown in the last year or two.
Fortunately almost all wineries that do charge will knock the cost of the tasting off of any purchase you make. (Fees average about $10 per person for a flight now.)
One of the bonuses of working in the industry, I don’t pay tasting fees (and get a nice discount on purchases to boot), so I never really pay attention to them.
I grew up in Geyserville/Cloverdale, and I can recommend quite a few not-as-well-known wineries in the Alexander Valley and Forestville areas that don’t charge (or at least, they don’t charge for basic tasting).
In Geyserville area/Alexander Valley:
Trentadue (good for port)
Pedroncelli (my favorite! and still family owned)
Murphy-Goode
Geyser Peak
Preston
In Forestville area:
Martinelli (fantastic Gewurztraminer)
Topolos (another favorite)
Korbel (at least last time I was there they didn’t charge)
You could also go all the way up to Mendocino county, but I’m not as familiar with those wineries (other than Fetzer, which I think doesn’t charge for basic tasting).
I’ve never actually even been wine tasting in Napa County. I prefer to stick with northern and western Sonoma County (not Sonoma the city) because, for the most part, they aren’t nearly as nose-in-the-air and have better wine besides!
Thanks for the posts so far! 
The Mrs. and I aren’t snobs as far as wine goes. If it has a tasting room, we’ll stop in!
Hell, last summer I had too much vacation time accrued and had to use it or lose it.
With no real plans we jumped in the car and drove west. Nobody really considers Iowa and Nebraska as wine states, but we found almost 3 dozen wineries between the two, and all but 2 had free tastings (the 2 that didn’t were only $5 and let you keep the labled glass as a souvenir!).
If you are open to Sonoma County there are definitely more options for you.
Check out these sites for more info:
Russian River Wine Road - You can search the wineries by any number of criteria, tasting fees included. There are great maps and day trip plans as well as lodging and restaurant suggestions.
Sonoma County Vintners - much like the above site, only covering the entire county.
Metroactive - A few good winery reviews from the 2005 North Bay Bohemian.
Wine Country Getaways - Another good site with day trip ideas, winery reviews, etc.