Who Can Help Me Optimize MySql ?

Hello , I Have a server and it host only 1 ajax site , when online users more than 70 ~ 100 server load is about 8 ~ 10 and cu usage about 45% ( Mysql Cpu usage about 35~ 38 % )
in this sitee eveery user in every second send about 5 ~ 10 requests and this requests run a mysql query and they receive 5~10 numbers between 0 and 99999999.
server details:
Cpu X3210 ( 4 * 2.1 Ghz )
Ram 16 GB DDR3
HDD : 500
Cp: DA
......................................
I user default my.cnf now!

can anyone help me to make an optimized my.cnf ?

Thank you very much

Google usually can give reply to your questions...

http://www.howtoforge.com/tuning-mysql-performance-with-mysqltuner

Regards

I'd rather install eAccelerator, tune MySQL as Andrea suggested, and probably some other settings...