Each week, we bring you our top picks for the best places to booze on the cheap in SF.

1. ThirstyBear Beer Education: The local beer purveyor, which is certified organic and brews sustainably, wants you to sample its wares-- on your lunch break. If you can undergo the office subterfuge necessary to sipping, you'll be rewarded with educational talks on sustainable brewing, plenty of free beer samples, and a great impetus to spend the rest of the day slacking off on the Internet. (Thursday, March 11, 12-1:30 pm, at Green Zebra Environmental Center, 50 Post St., Tenderloin.)

2. Tweservation at O Izakaya: Those wacky folks at Tweservation are at it again with the free happy hours, moving their merry band of restaurant-loving tweeters to O Izakaya, where they'll be rewarded with a free draft beer or glass of wine, as well as free edamame or fries to munch on. If you've been following them on their mission to spread free drink and fast table-snagging to the entire city, you know what to do: have a Twitter account and RSVP here. (Thursday, March 11, 7-9 pm, at O Izakaya, 1625 Post St., Japantown.)

3. $1 Oysters at Oola: Oola's convenient location, straddling the border of SOMA and the Financial District, makes it a good spot to gather after work. But in addition to $3 drafts and $5 wine and champagne during happy hour, they've decided to sweeten the pot with $1 oysters on Fridays. At the rate that the $1 oyster trend is going, even Swan Oyster Depot may have to start hawking mollusks for sawbucks. (Monday-Friday, 5-7 pm, oysters Friday only, at Oola, 860 Folsom St., SOMA.)

4. Flour + Water Free Corkage: It's aimed at industry folks, but all night owls can participate: when late night rolls around, corkage at Flour + Water, the insanely popular pizza and pasta joint in the Mission, is free. Though this deal is only offered after 10 pm on weekdays, we're totally fine with it, because that's the only time reservations are ever available at this place. Don't get too excited, though: there's a limit of 2 per table. (Sunday-Thursday, after 10 pm, at Flour + Water, 2401 Harrison St., Mission.)

5. City Tavern Has a Ton of Deals: Veteran cheapskates have long been familiar with the siren charms of City Tavern, seemingly the only place in the Marina devoted to the health of our wallets. Having realized that many of our readers are not acquainted with their deals, it bears repeating: on Tuesdays, this place is a rightful zoo, with $2 beers of all kinds, and numerous $2 foods (burgers, pizza, chicken wings, salad). Thursdays are slightly pricier, with $3 buying a well drink or one of a more upscale selection of dishes (quesadillas, calamari, spring rolls). And on Saturday, your first mimosa is free with brunch. Whew. (Tuesdays, 3 pm-12 am, Thursdays, food 7 pm-10 pm and drinks 7 pm-12 am, Saturdays, 10 am-3 pm, at City Tavern, 3200 Fillmore St., Marina.)