Automated Aggregation?

In the interests of offering one-stop shopping, I figure I should cross-post here pretty much anything I blog anywhere else (as always, by category). Frankly, though, it’s tedious to cut-and-paste or even post through the aggregator (plus my LiveJournal’s RSS feed is headlines-only). I wonder if it might be possible to write a script to watch my news feed and automatically post to pre-specified categories entries from my other blogs?
I know one day I’ll probably have to settle on a single tool and run everything through it, but I consider this market research, a learning experience, and something of a teaching exercise as well to explore as many options as possible. So, in the meantime, I’d love to employ a drudgery-free method of pulling together all my x-pollinations into one place.