Where Do I Put a Script I Want to Run at Startup?

[springshades]

Mostly just the subject of the post. I want to be able to run a couple lines of script at every startup. It will require root priviledges. I'm not sure where to do this. In Windows I'd probably throw a batch file in the start up folder, is there anything similar I can do in Linux? I'm wondering if I can put a couple lines of script at the end of the inittab file or whether that would cause massive amounts of damage to my system.

Basically the CPU in my laptop starts out at 1.2 GHz while booting and I'd like to automatically have it go down to about have that to save power and lower temperature once it is done booting. I'm planning on controlling CPU frequency manually.

Thanks.

[falolaf]

try:
/etc/rc.d/rc.local