Noticed a small puddle of oil under the truck. Seal on the oil filter is tight. Any suggestions? Truck has 35,000 on it.

You too huh? I have an 04 1500 4x4 as well, with a 4.7 in it - it developed a leak in the transfer case at 15000, dealer hasnt fixed it yet (It has to be taken off the truck, case halves separated and re-sealed....) and now at 30k I have another at the seal where the steering shaft meets the rack & pinion mechanism....I have a 1996 Jeep that I wheel and beat on that leaks less, with 140k on it.....sheesh.
Best I can say is keep the fluid levels up to where they should be, and get it to a dealer that won't jerk you around. - If I had time to tear mine down myself I would, but with it being 5 degrees out, no garage to use, and it being under "warranty" (I use the term loosely) I will let the stealer do it.
As far as trackin down the leak, try to see what type of fluid it is atf?, oil, brake fluid, if its a puddle under the front axle and its reddish fluid its atf - used in the power steering pump on this truck, if its brownish its motor oil, if it stinks its gear oil ;-), take a good look at all the seals on the front axle, the ps pump, etc, see what is wet with oil. Thats where I would start at least.

Like artyart said, gotta track down the leak, or just bring it to the dealer and let them do it. Personally, I like to know what is wrong with it before I bring it in.

You can use leak dye. Pour it in, turn the lights off in your garage and put a black light in your drop lamp. Leaks glow when you shine the lamp on them. Works great.

Who sells it and how much?.

Napa has it for a couple of bucks. It isn't really expensive, but you need a black light to make it glow.

I ask for it at AutoZone, they tell me that they don't have it. I tell them they do, they out back for at least 10 minutes then come back with a small dusty bottle of dye. Done this three or four times.