I love the St Marks Trail! It's a great way to spend a sunny day with plenty of sunblock, water, and some good friends. I've biked and rollerbladed it, and also gone horseback on the unpaved trail and had nothing but good experiences. Other trailblazers are usually very nice and courteous and there are a few rest areas/water fountains along the way. If you have a mountain bike, there's some neat trails between Tallahassee and Woodville that you can access from the trail. If you work up an appetite, check out Posey's oyster bar or Riverside Cafe (which are hard to miss at the end of the trail) for refueling or enjoying a lemonade or sweet-tea before trailing back (I'm not sure if these are still open because the area was hit hard during hurricane season last year). There's also the San Marcos Historic State Park at the end of the trail that has a nice picnic area and canoe launches into the St. Marks/Wakulla Rivers. Depending on where you start from the trail can be up to 19 miles long (ending about 3 miles into the city), so plan accordingly. There are no admission fees and you can park at any of the rest areas along the way.