Having great luck working with single-source feed parsing in Universal Feed Parser, but now I need to run multiple feeds through it and generate chronologically interleaved output (not RSS). Seems like I'll need to iterate through URLs and stuff every entry into a list of dictionaries, then sort that by the entry timestamps and take a slice off the top. That seems do-able, but pretty expensive resource-wise (I'll cache it aggressively for that reason). 
Just wondering if there's an easier way - an existing library that works with feedparser to do simple aggregation, for example. Sample code?  Gotchas or warnings? Thanks.
Here is already suggestion to store data in the database, e.g. bsddb.btopen() or any RDBMS.
Take a look at heapq.merge() and bisect.insort() or use one of B-tree implementations if you'd like to merge data in memory.
Aggregating multiple feeds with Universal Feed Parser