this was posted about a week ago, in a thread about this :
robmcl (Instructor) Jan 21, 2004
Hi folks...just found this discussion and thought I'd add some of my own experience...fwiw...
I also prefer TMPGEnc for encoding (best quality I've found) and yes, it normally needs an uncompressed AVI (which I used to export from Premiere).
I have recently found a product/method called "frame serving". There are several products that perform this function as a Premiere plug-in. Basically, you "export" your timeline to this plug-in, then start up your TMPGEnc. The plug-in will literally "serve" each frame of your timeline from Premiere directly to TMPGEnc (hence the term "frame serving"

. This completely eliminates the time (and disk space) req'd to export an uncompresssed AVI before encoding to MPEG. It does work...and very well!!
There are several products, but the one I like (and now use all the time) is called PluginPac FrameServer by debugmode.com
Give it a try...you'll like it
Rob