For those of you that are builders, you may find this helpful. (Or invaluable.) It's a HUD that allows you to search through a database of over 30,000 megaprims, and sends you the size you ask for. Apparently, if it can't find the size you want, it suggests something close, though I've not encountered that yet. It's very easy to use, too, with no obnoxious dialogue menus or buttons to deal with it.

Oh, yes, and it's free. HUDs stress me out, but I swear, I'm never taking this thing off.