20 amp 125v plugs have a different prong configuration than 15 amp plugs/receptacles (one is turned 90°) so unless you have a 20amp receptacle to plug it into, you will have to simply use a standard 15 amp plug. I would still use a 10 gauge cord because a smaller gauge wire could add resistance that can cause a trip too. Keep the length to the minimum you need to reach where you may have it sitting when you use it.
Note that on the power strip that Kenny linked to, the receptacles on the strip can handle both 15 and 20 amp plugs but the strip's plug is just a 15amp one. Not quite sure what the point of THAT is.
BTW, don't get confused between a 125v 20amp plug and a 240v 20amp plug. They look very similar but are not interchangeable. The 240v version (5-20P) has the opposite prong rotated 90° than the 125v version (6-20P).
--Nathan, TX. Hire the lazy man. He may not do as much work but that's because he will find a better way.
