possible reasons for coolant leakage

chances is the rad is cracked,if its coming of the side of motor it can be the water pump,obviously ide have to look to see but it cant be too hard to see,have you just had the coolant replaced maby its just trickling,make shure your not overheating

3.4 v6? How many miles? If near or more 90k miles, I can bet you dollar for dollar that the water pump is out. You have to change the timing belt at the same time.

If you can't find it, take it to a mechanic for a pressure test...

There isn't a timing belt on the V6 2nd gen. It is a timing chain. No need to replace anytime soon. Checkout my post about timing belts: http://www.tacomaworld.com/forum/technical-chat/19496-timing-belt-timing-chain-all-toyotas-toyota-com.html

Sorry I didn't notice it was a 2000 1st gen. Yes it is a belt. Do as Phillip said, replace the water pump,timing belt, & hoses at the same time. It will save money in the long run.