Please meet: Hong's Hangul Conversion Tools. Type in some hangeul and it'll spit you the romanised equivalent (transliteration, not translation). More importantly for my needs, type in the romanised word and it'll give me the hangeul character that I need to add to my text.
The second one is a no-brainer: Google Translate, which has received enough queries from my computer to default to offer Korean-English translation.
How on earth did people do things before the internet? (Rhetorical question.)
Edited to add (Aug 8): The Korea Times reports that an Indonesian tribe in Sulawesi has chosen to adopt hangeul as its writing system (via The Marmot's Hole).