Very often users need to check some main process on server, that can eats too much CPU. But at now Zabbix can check only total CPU usage. Will be good to have item to get cpu usage per process.
In linux you can get this info via command:
$ pidstat -p <pid>

1. pidstat -p 31228
   Linux 2.6.32-bpo.5-amd64 (host) 11/13/2010 x86_64

11:46:03 AM PID %user %system %CPU CPU Command
11:46:03 AM 31228 1.53 0.36 1.89 1 mysqld

And will be good to have items for monitor per process cpu usage history, values - utime and stime:

utime - Amount of time that this process has been scheduled in user mode, measured in clock ticks
stime - Amount of time that this process has been scheduled in kernel mode, measured in clock ticks

for get them, you can use the comands
$ cat /proc/<pid>/stat | cut -d' ' -f 14 #utime
$ cat /proc/<pid>/stat | cut -d' ' -f 15 #stime

Can you add thouse values to zabbix items?