I don't know, I usually just head into the city and see if I can't find something to do. Catch a new band, see if I can sit in anywhere and play, drink my body weight in whisky...get high...try to pick somebody up...try to get arrested...call up friends...sex...usually by the time I run through that list I'm not feeling so lonely and bored anymore.
Although I guess with the small town blues setting in (I know how that can be)...movie night? Dig into a good book (hitting up the library is always fun), I always enjoyed drunken target practice in the back yard, that probably doesn't work so well with an apartment though. Actually when I lived in bumfuck Maine I used to love night time drives when I was lonely and bored, put on some good mellow music, hit the gas and just see where you wind up. Discovering a new lake or beach I'd never visited before was always a good distraction.
God do I miss sitting on a quiet beach under a full moon, joint in hand, fire, surf, the smell of salt water, a couple of good friends...those were great times.