There's a respec potion in the game files, but you can't access it normally. You can either spawn it with the console (not recommended), or get a mod that adds it. You can download the mod from the URL below.
They didn't want it enabled by default, but then the community asked for it, and thus they added it in the form of a quick mod. ReSpeccing is generally frowned upon by "purists", so they wanted the purists pleased first, and the other crowds pleased second. Either way, it's a Win-Win situation for them.
I think for your first ever character they should allow 2 respec potions in your stash, after all we are all new to Torchlight and bound to nake some mistakes with skillpoints or just curios to try things out. And as usual a skill that looks great on paper might suck when you actually get round to using it. Does anyone know if there is a limit on the number of characters you can start, I'm sure the MMO version would have this restriction but maybe not the single player game?
Spawning the respec potion through the console would label me a cheater and delete my shared stash, and the aforementioned mod simply crashes my game on start-up (C++ runtime error, which only happens in this particular case).