Many people have done this mod. However, there have been occasional reports from 2G owners that the 100W bulbs drew enough power from the car to damage the headlight wiring harness.
To combat this problem a few people have rewired the headlights with larger gauge wire. Curt Shambeau did so on his 1996 Spyder convertible and reported an increase in light output of 250 foot-candles on both stock and aftermarket bulbs. For the electrically inclined, this is obviously a good modification. For the non-electrically inclined, some companies now market plug-n-play wiring harnesses to upgrade your wiring. Often marketed as "SUV" or "heavy duty" lighting harnesses, they usually come complete and ready to put in.