You can fit real gas discharge lights. Haven't done it myself but have read plenty of very positive reports from those that have. These guys seem to have a very good rep and they're UK based:
http://www.hid-online.com You retain the stock headlamps and fit a modified bulb/lamp assembly to them. The kits come with everything you need including bike specific wiring harness, igniter etc etc.
[Edited on 7-4-2004 by neil748r]