I've been looking over the various guides for mining on Ubuntu 10.10, 11,04, 11.10 now that I've upgraded my system

AMD users installing Ubuntu 12.04 get a variant of the Catalyst 12.4 drivers, which IIRC already has the AMD SDK included or some variety of baked-in OpenCL support that previous versions haven't. That sounds like a significant enough difference to break all previous how-to guides.

So are there any suggestions for getting up and running on the new Ubuntu LTS?

I was using phoenix on Ubuntu 10.10 before thanks to this howto... how much of it is still applicable? What do most people install for mining now? I have a Radeon 5850
http://foreverrising.wordpress.com/2011/04/16/bitcoin-mining-and-ubuntu-10-10-ati-radeon-5xxx/

Thanks!