Question: I have many Linux servers (SUSE 9 &10) used to run web services that provide data to large calculation grids. Recently we have had some difficult to explain outages (i.e. hardware and software logs are not showing any obvious errors) and we are starting to wonder whether the long uptime (typically 200-300 days) is the issue. Given that these servers are heavily utilised, should I consider a regular reboot cycle?

Answer: 
Its not a bad idea to reboot if it has been that long so you can run a disk check ( fsck ) on the root partition. Your argument can be that this helps ensure data integrity.
A properly run Linux server should only need rebooting for kernel updates. The same can't always be said for some of the software - for instance, I sometimes have to restart apache2 or mailman.