Depending on what type of music you like to play, look for open jam sessions around town. I realize it's not high on the "easing social anxiety" scale, but if you go a few times first just to listen, then come to play, you'll be comfortable with the people, and have some idea of the level of playing that's expected. Such jams are always in need of bass players, so you'd be a welcome addition to just about any of them.

Check local music store bulletin boards. Also, hang out at the store some and get to know the guys behind the counter. They may know somebody who's looking for a bass player.

Craig's list.

I'll think about others, but those are the old standards.