Honestly, I can live with reboots on my home server when a new kernel is applied, but I can see its appeal in more demanding environments. The good people from kspice have written a utility that manages to apply kernel patches in situ meaning that you don't need to reboot when patches are applied. As it is free for Ubuntu 9.10, I thought I'd install it on my server and see how it gets on.
Download and install instructions are here and are a piece of cake.
10/10 for simplicity and I'll be interested to see how it goes.
My uptime, such as it is, can be monitored here.
I see that howtoforge have added a article for this. If you like pointy-clicky instructions, then this is the article for you.