You do not have to upgrade every six months. This is a mistaken idea that just
because Canonical has set a schedule to improve the OS with six month upgrades
you are on some upgrade roller coaster. You can stay with Hardy Heron until
April, 2011 for the desktop version and until 2013 for the server edition
without worrying about chasing the newest version and you will still receive
full support from Canonical. With Ubuntu you have a choice. You can upgrade or
stay with what works for you.

An alternative would be to use Debian. Their stable release moves at a glacial
pace if that is more to your liking. However, treating Ubuntu as a rolling
release has the same effect as using Debian Stable. Ignore Intrepid Ibex in
October and whatever comes afterwards. Some people are still using Dapper Drake
until next spring when it runs out.