Since I'm only visiting Berkeley and don't really have a home to call my own, I've been spending a lot of my time wandering around the town looking for places to write. In case you ever find yourself in this situation, here are my reviews of the local hangouts.
Bittersweet Cafe (on southern College Ave): Nice atmosphere and delicious snacks, but a little pricey. Also, with the limited seating, you can't really in good conscience hang around there for hours and hours working on your NaNo. The coffee is excellent...they don't serve Blue Bottle there anymore, but their new house brand is almost as nice. The real draw is the assortment of gourmet chocolate-based drinks.
Semifreddi's on Claremont: The music was too much in here. Oldies. I didn't write anything. Staff a little brusque. Good sandwich.
Doe Library (on campus, head upstairs to the reading rooms, no student ID necessary): Ample seating and ample electrical outlets. Beautiful space. Excellent for getting things done, because there is no internet access (unless you are unfortunate enough to be a student), no drinks, no snacks, no music, no talking...no anything really. Please note that if you have a Mac laptop, you should bring the extra extension cord, because there isn't room for the square white adaptor thing to plug in.
People's Cafe (Shattuck Square): Ample seating and ample outlets, no distracting music. Coffee is pretty bad, pastries are nothing special. Mysterious collection comic books (several file-boxes of them, probably hundreds of issues) in storage in the bathroom. Free internet.
Berkeley Espresso (Shattuck and Hearst): Get there in the slower hours to stake out a seat near an electric outlet. Tons of people bring their laptops here. The coffee is tolerable. Snacks are nothing special, although they do have some decadent cheesecake things and the variety is good. Tends to play inoffensive classical music. Good selection of tea. Can be a little noisy. Free internet.
Fertile Grounds (Shattuck at Delware): Great coffee (Illy Espresso). The pastries are nothing special, but the falafel pita is excellent. Cute dude works there. Seating is limited and a bit uncomfortable. Never noticed any music. Rotating art exhibits. The chairs tend to be a bit too hard for prolonged writing.
Village Grounds (across the street from fertile grounds, in the coffee pun district): Haven't had the coffee, but the mint tea is pretty good. Nice morning buns, ample outlets and seating. Drawback: classic rock station playing loudly. Free internet.
Cafe Strada (College and Bancroft): Run by Cafe Roma which also runs some other cafes in town. They make a gut-scouring cafe americano that I am pretty fond of. Some of their pastries are good, in particular the apple harvest cake. Indoor seating is very limited. You can usually get a seat outside, but there are no working electrical outlets (you will see outlets, but don't be fooled, they don't work). This is my favorite place to work on a nice day.
Mo'Joe (Sacramento and Dwight): This was the site of my failed NaNo write-in. To be fair, it was raining. They have some comfy chairs and outlets. The pastry I had was very mediocre...it was a pumpkin cheesecake tart with a white dome-shaped garnish on top. I thought the white thing would be white chocolate, but it had more the consistency of a flavorless milk-based gummi. Staff didn't know what some of the items in the pastry case were. On the bright side, they served me really nice herbal tea in a personal tea-pot, one of those glass ones with the built in press. That was nice.
Au Coquelet (University and Milvia): The big draw of this place is that they're open late. Watch out for crowds on Friday and Saturday nights--this is a big venue for after-parties, especially Gaskells. Decent beverages and seating, some outlets. Some good pastries (carrot cake) and some terrible ones (anything in a tart shell). Unlike other local cafes, this place has some wine and stuff on the menu.
Brewed Awakenings (Euclid and Hearst): Lots of seats, but this place is popular, so it can fill up. Good supply of electric outlets. I had a good pastry. Tea was average. Didn't try the coffee.
In writing news, we were sent a NaNo "pep talk" likening the middle of one's novel to the middle of Australia. I can dig that.