Why ompile your kernel? Just one thing, that comes to mind. Hotplugging USB devices took my box a minute or so, and it now takles only 5 secs after I only left the support for the USB dvices I use.
And the overall loading of my box was reduced from 1minute 30 seconds to 23 seconds
The trick is to compile into the kernel only the things you need at boot time (like ext2 support and such). Everything else is best compiled as modules as it leaves the kernel intact and light (and FAST).
Sorry if this is not the thread to post this into.