high average load and kernel recompilation

[Pol]

Probably due to many applications always running, the average load of my 
laptop, as reported by the 'top', is constantly around 5-6, users' cpu
percentage being around 90%, with no special application taking most of
that.
Machine is hp tc4200 laptop, 1.7 GHz (but i am used to keep it
in 'powersave'
mode, at 0.8GHz) , 1.5MB ram, 2GB swap.

About running processes:
As i log in, several system services are started: postfix, dovecot, dictd,
hpoj, wooffle, collectd. I one of my attempts, proxy was disabled in
webbrowsers, with no change in performance, so my guess is that wwwoffle
should not affect the average load.
After log in, a few applets (kbandwidth, clock, calendar, systray), two
konsoles monitoring log files with 'tail -f', amarok are started and, from
a few more konsole sessions, 'sudo su' to four more users. 
So, there are five users, each of which starts konqueror, connects to gmail,
opens a few pdf files, starts kalarm and kgmailnotifier; sometimes lyx
editors and maxima (symbolic computations, spending most of the time as
idle) are started.
One of those users starts ktorrent; another one starts knode; another one
starts firefox (connecting to gmail and opening several google notebooks)


Any hints to lower the load?
Would kernel recompilation improve performance? (i am using kubuntu 8.04.2,
kernel 2.6.24-23-generic)

Thank you
--P