I'm signing up for Slicehost right now because I want more freedom with my server. Storage and bandwidth I don't care about much, because I don't do very much transfer-heavy work on my own sites, but how do I judge how effective their RAM offerings are? How much memory does a single hit to a site take? How many concurrent threads can be run with, say, 256MB of RAM versus a full GB? I don't recall ever reading about this before (other than "X site goes down thanks to Digg effect) and I was wondering if anybody had advice about figuring out which would best work.