Hi! I'm coming to SF next week for a conference and staying a few extra days with my boyfriend. I've been following your board for months and have read so many of your excellent recommendations. But we're hoping to be economic (and trendy) by filling in our lunches with the food carts. I've learned that you need a Twitter account to find them (got it!) Which ones do you recommend I follow? We're staying on the wharf for the three days of the conference, but after that have more mobility, including staying one night in Berkeley. Thanks!