I just went through a couple of years of posts, tagging some of those written before I introduced categories to Leonardo (in particular, the ones about Alibi Phone Network). It occurred to me that this categorization could be a job for machine learning.
I've talked before about using techniques like Bayesian Classification for identifying posts in an aggregator that one might be more likely to be interested in. But it didn't occur to me until now that similar techniques could be used to suggest which existing categories to place uncategorized entries into.
At some stage in the near future, I'll try a quick implementation in Leonardo and see how it goes.