For those who want to try this, this is how I got "Jems" working...
Unzip the link/file in the first post above into a Jems folder. I put it in C:\Jems. ALSO copy the whole link/file into the Jems folder. Make sure that that file is renamed from jems.zip to jems.jar
You should now have three files and two folders in the Jems folder.
Do a Start/Run and type "cmd" in the open box.
Type "cd C:\jems" or use where ever you put the jems folder.
Now type that line from above,
"java -classpath Jems.jar com.tivo.hme.host.sample.Main com.tivo.hme.Jems"
If it works you should get, "HME SDK 1.4 (TiVo, Inc.)..."
Check your TiVo's Music, Photos, Products and More..."
Find "Jems" and play away . . .