Sensible thing to learn to do, since most of the guitars around are strung right-handed. I've occasionally had a go at a left-hand guitar, being right-handed - it feels really strange, but it could be fun. Maybe sometime I'll string up a guitar of my own left-handed.
The other thing I've thought of is trying a left-hand strung mandolin, because that'd give you the same string values as the bass four strings on a standard guitar, but in reversed octaves, and standard guitar chords would work, but sound comnpetely different. Anyone ever tried that? (So far I've never run into a left-handed mandolin.)