Gridskipper is a fantastic resource for finding not-so-touristy things to do in many cities, both in the US and abroad.  Each “post” has a city tag and often another tag such as “shopping” or “nightlife”.

I used this on a recent trip to London and found a neat coffee place called Flat White, which is an espresso shot in a small cup of milk.  Also worth checking out is Red Veg, a vegetarian restaurant in Soho.  They have breaded sweet corn.