Anyway, I've written a little tutorial over on the Snark Pit on how to use vertex manipulation and/or Align to View to help align textures across 'curved' surfaces in HL. There's a specific example at the end showing the technique used on an ns2.wad texture, but other than that it's relevant to anything Hammer-related.
It's nothing revolutionary, but has some information some people may not know about... Thought I'd toss it up here.
http://www.snarkpit.com/editing.php?page=tutorials&id=80
Hope someone finds it useful.