Years ago, there was a semi-clean file-sharing program called KaZaA Lite which, despite the dwindling number of users near its end, was surprisingly effective at finding & downloading MP3's, especially high-bitrate versions, when used in conjunction with KaZooM.
A KaZooM equivalent is what's missing from LimeWire. When LimeWire's dormant downloads eventually stop looking for sources, they'll sit there until the program is restarted (pausing & restarting is rarely effective: LimeWire needs a 'reboot' before it will start finding & downloading again).
When the KaZaA Lite/KaZooM pair was running, KaZooM pinged on each inactive download & told it to go out and look for another available file source. By doing that, it eliminated most of the downloads that might have otherwise ended as dead or partial downloads.
Despite a feature in LimeWire that tries to do the same, it just lacks something that KaZooM had, namely the ability to see that a download completed.

Does anyone know of a KaZooM equivalent for LimeWire?

It would be fantastic to end the WAITING FOR SORCES procedures in Limewire and have a program which takes care of its users...
I would like to mail this idea to Limewire and the Gnutella network...