QUOTE(greynol @ Apr 9 2008, 02:15)

Please
search before asking questions that have already been asked before.
Anyhow, I know of an easy way to make sure your mp3s aren't transcoded from lossy sources.

I'm interested in how to tell transcoded MP3s as well, but the search option you gave, for the first 2 results, it hasn't been solved yet. It seems that you need to read the source in the Lame tag, but there isn't a way to read it.
BTW, In Encspot, what does the "original" checkbox mean? Does it mean if it's ticked, it is not transcoded?