I've hacked up all kinds of interesting things in Excel. Every time I embark on a new hack, I try to learn some new thing, but the help file is not organized by user advancedness, nor does it say "I notice you're trying to look up a value in a table. Did you try VLOOKUP()?"
Anyway, just when I was not hacking up Excel, I stumbled across this gem: Exploring Excel's Functions Part 2: ADDRESS() and INDIRECT(). I can't believe I didn't know about these Really Useful Functions.