Sure, there are always the trails around the lakes--but pulling Pooch off a rollerblader's legs is only fun so many times. If your canine's well-being (or your insurance bill) demands a diversion, leave the leash at home and head out to Hennepin Parks' Elm Creek Reserve. Tucked away at the end of a trail off County Road 202 is the oldest, and still the best, of five off-leash parks in the metro area: From 5 a.m. to sunset, romp in 30 acres of prairie and swamp, with lots of fascinating-smelling wildlife tracks and a nice, tall fence in case Buster takes a mind to head for Wisconsin. Of course, freedom doesn't come entirely without responsibility: Dogs must be under voice control, there's a $25 annual fee, and, no, the grass doesn't appreciate a little extra fertilizer. In fact, excess nutrients could ruin the park's newly created wetland. So bring a bag.