Well I'm quite fond of "interesting" herbs. Especially of the culinary, medicinal and folkloric (ie: 'toxic') variety... :-)

I've considered growing Saffron Crocus (Croci?), but just one of those things I've not got around to experimenting with as yet. I'm sure it'd be a sound idea though. As bulbs reproduce naturally. So I'm sure a small patch would suffice for ones future saffron needs.