The main ways to speed up SETI would be:
1. Use the command line version, not the regular graphical one.
2. Overclock your system especially the RAM as much as will run stably.
3. Turn off all power managment stuff especially as related to hdd.
4. Use a caching program to help you keep going with you can't reach the Berkeley servers.
5. Run your system 24/7
6. Join a team like ours and the competition will force you to build new systems thereby increasing your daily work unit production!
HTH
Cy