Clearing the log files

Is there a way to clear the log files? When I check access and Error logs, I want to clear them to see if the errors are regenerated again.

Also the formatting is not very good, there is no line breaks in the log file viewer. Some coloring is also nice!

Logrotate is a standard linux message handler, that all sysadmins should know about.
CWP even provide lusers with a GUI to manage it, if command line is too scary.

[From your other post about notifications, you don't care about security, so may as well ignore system message too. :p]