Hey david,
Graham Swamp has some good trails. There are two entrances: one on Old Kings Road, left side, about a mile or so past Utility Drive. The other is on Colbert Lane, about 3 or 4 miles down, (right before you come to the old cement factory), on the right hand side.
Linear Park is pretty good, but not great. I run there a lot though, because I feel safe there, also because I prefer asphalt to concrete. There aren't any real trails there, except the "mountain bike" trails, some of which I recently found. The sand/shell paths are pretty good though for running on... gives a nice break from pavement, but they're a bit short. (the longest one being .42 miles, I'll run that one back and forth several times).
Princess Place Preserve is good for running too. The High School has held a couple of cross country meets there. Quite a few dirt roads (I drove through Loop Road... nice drive underneath the oaks, so I'm sure its a lovely run!) going in different directions with public access (be careful though, because some areas are private property, but there will usually be a gate). When you drive into the Preserve on princess Place Road, before you even reach the Lodge by pellicier creek, and right before you cross a small bridge, there's a spot called "The Hill". No, there's no hill... at least I haven't gone far enough to see one! But you can park there, And there are two trails there that connect with each other. Red Trail is 2.29 miles, Orange Trail is 1.45 miles.
Also at Princess Place, is equestrian trails which I'm sure you can run on... but watch your step for obvious reasons. Also, on the main road, if you follow the signs to "Green Trail" there is a small bridge that connects to a small island, and there is a trail that goes halfway around it ("Island Trail"), and Green Trail is nearby, and its a little over a half-mile in length.
Here's a map of the area... its not very good, but it gives you a general idea:
http://www.flaglerparks.com/images/pppmap.jpg[/URL" target="_blank">
http://www.flaglerparks.com/princess/hikingmap.pdf[/URL" target="_blank">
Good Luck on your running!
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Today, I will do what you wont, so tomorrow I can do what you can't.
http://This message has been edited by pckelly (edited Oct-23-2006).