We found some really great games for the dreamcast: Bomberman Online and Samba de Amigo. Both of these games are NTSC games, and Samba De Amigo is in Japanese! Those games won’t play on PAL dreamcasts, so I applied the Region Free Mod on all four Dreamcasts (more controllers welcome!).
The mod has been documented in by Daryl Kerr. With great detail he explains how to apply a simple wire between two components on the motherboard. Adding this wire requires some careful soldering, yet isn’t extremely hard.
After applying the wire the region settings (NTSC/PAL) can be changed with a software CD. This means you can play all dreamcast games ever made worldwide. Handy for all those games that never made it to our part of the world.
In the end, this is what it looks like (picture made by Daryl Kerr):