Running Gear: GPS for the phone

i have a palm centro for att and i want to get a gps app for it for when i run. i don't want to pay a monthly fee. if there is one where i can just pay 1 time and then i have it that is ok. but i really want one that is free. if you guys know of a place where i can get a download for one or where i can buy plz tell me 1)don't want monthly fee 2)1 time fee is ok 3)really want a free one remember i have a palm centro