I was involved with a couple last year, and it was fascinating to see how various contributors viewed them.

There were obviously the bedroom enthusiasts that wanted to have a go, then there were bands that were fans of the act in question, but then there was the unexpected third element - signed acts with no released material that were encouraged by their management to contribute solely to get their discographies off and running. One act even used the opportunity to vet the producer that had been approached to produce their debut single.

I suppose it's a quick and easy way for bands to get used to the studio recording process, eliminating the need to have their own material 100% ready, but it hadn't struck me that this was something the industry had cottoned on to, and for a variety of reasons. Worked a charm for us as well, as the unexpected contributors' MySpace connections lapped up the CDs.

I know a hell of a lot of dross has been produced in the name of the "tribute", but have other posters come across similar examples of the industry using such projects as, I suppose, work experience?

The first thing that I wanted to do was , make what you refer to as a tribute album, completely different to the mainline industry ones, and i think I know which ones you refer to, into a complete album as opposed to an album that you skip through.
The second thing, was I did not want to offend any fans of the original recorded work, which I think often happens.
The third. Showcase as many new acts as possible. Fourth. Give all the money to charity.
And the final and fifth thing was that I wanted to genuinly poke the eyes of cabaret tributes and lookalikes.
I found very few bedroom recording enthusiasts, although everyone was responsible for their own work, all the acts work live.
However, in answer to your question re-work experience, I just wanted to see if it could be done really, in a tight deadline, so you can judge for yourself on that one.