Not sure if this has been put on here before (Couldnt find it on search), but found this trick on AV Forums to enable to USB slot on the back of the LG 42LH3000 LCD TV. The higher spec TV's have this enabled, now you can have it too.
Means you can plug in any USB device (Ive got an NTFS formatted HD in mine at the moment), and play back xvid, dvd rips, mp3's, MKV's, JPEGS and possibly more...
1) Press and hold the OK button on the remote AND on the TV at the same time, hold untill password screen pops up.
2) Enter the default password 0000
3) go to option number 3 and set jpeg,mp3 to 1 and divx/xvid to HD.
All done. Mine worked a treat, and makes me happy inside. Gives you a nice liile menu system aswell, making it easy to find your files.
Remember, you are messing with the service menu. Use at your own risk, and change only the things on this guide. You should have no problems....