Looking for a little girl-on-girl action? Then head over to the 20th Street Recreation Center on Wednesday nights for the women-only boxing class. For one hour a week, a half-dozen street-savvy ladies practice their right hooks, uppercuts, jabs and roundhouses. Although this is strictly a no-contact class, 20th Street is a serious boxing gym, with fighters in the ring around the clock. So don't expect some chichi tae bo or kickboxing class -- and don't forget to bring shampoo and conditioner, because the locker rooms are the epitome of stripped down. But for just $5 a class or $125 a year (includes access to all of Denver's recreational facilities), this is a deal that kicks serious ass.