Woe is the lowly and now discontinued (except for Education customers) eMac. Compared to its sleek and sexy brethren, the eMac has always felt to me like the kid picked last for kickball.
But like Clark Kent turning into Superman, your eMac can be transformed into a pretty powerful beast. Here are instructions on how to overclock
that 800Mhz eMac to 1.33Ghz. You can even install a Superdrive, add several extra internal HD's, and hack the firmware to allow for dual monitor support. Be sure to check out the extra links at the bottom of this page for other eMac overclocking instructions.