Hm, now this is a tricky question for me (and probably a lot of women). I'm an over-giver, and generally think about everyone else first, then myself last.
However, I have a great husband that supports whatever I come up with... I want to go get a pedicure, he says 'great!' (and usually wants one too - I love it!). I also have great friends that like to meet for lunch, and I'll take an extra 30 minutes after lunch to either walk around downtown myself or maybe pop into a favorite shop for some drooling.
When I really need to recharge, I generally have to be by myself. Whenever I grab a romance novel, it's my husbands cue that I'll be 'absent' for a day. I devour them within hours, and can take myself into another world and relax. Tune all else out and ignore everyone/everything.
Otherwise, I really like to do most other things with people and as long as I feel like I have a good balance of different activities going, I don't feel like I need 'time for myself'. Those activities are what I do FOR myself, for fun and they are what keep me going and excited each week.
To read other bloggers ideas on how they take time for themselves, visit Jolly Mom or Go Graham Go!