Join Date: Aug 2002
Location: Brandon, Florida
If you're not as motivated as myfirstcar66 you can pull the filler hose off of the tank in the trunk and shine a flashlight in there and get an idea if it's rusty or not. You can even shove a little camera in there if you've got one and you don't have to drain the tank or anything. If it looks nasty in there you'll know you need to order a tank.
Still, don't start any fires or breathe too many fumes or anything like that. Well ventilated area, etc etc.
If the tank's not rusty or dented the problem is probably just your sending unit. You can try and clean it or you can replace it (search around here, there are plenty of sending unit threads) but of course that's going to take draining the tank.
Before you start breathing all the gas fumes though make sure it's not the gauge. It's probably not, but it doesn't cost anything to check. While you're under the car looking for dents pull the wire off of the fuel tank sending unit and ground it to a clean spot on the body somewhere. Then go turn the key to 'Run' or 'Accessory'. The gauge should go all the way to full. If it does (and it probably will) you know the issue is with the sending unit. If it doesn't, definitely fix the gauge first since that doesn't involve dropping dirt, rust and gasoline in your face and all that.