Ok guys, so I really don't know how I got to this point, but it literally took countless hours of reading up and messing around. (Note: this was done with my 3G. Not sure about 3GS 0or 2G, thought I don't see why it wouldn't work). Originally, I only had the AT&T carrier file (.ipcc) 5.0 version used in the last 3.0 beta, which enabled tethering. If you attempted to configure the network settings for MMS, however, tethering would break and no longer be an option (on 3.0 final the tethering option would simply disappear). Also, Visual Voicemail would sometimes break for a lot of people, so it seemed like you could only have 2 of the above 3 working together. So i messed around with a couple other .ipcc's till I landed on one which gave me all 3 (don't ask what I did exactly, cause I don't remember every step). I did a little mixing of .ipcc's to make sure that allowing a combination of 2 of the 3 wouldn't break the 3rd feature. I have uploaded here my ATT_US.bundle, which gives you the camera (MMS) icon in messaging to allow for MMS (which is also already configured in network configurations, so you don't have to mess with any manual settings), Tethering is enabled and configured and Visual Voicemail works 100%. You'll need to SSH into your iPhone: /private/var/mobile/Library/Carrier Bundles and replace the ATT_US.bundle with the one I uploaded (backup your other one just in case). For those wondering, no, I DID NOT HAVE TO CALL ATT FOR ANYTHING. In fact, looking at my bill right now, i still have an iPhone data plan + MMS OPT-OUT. Tethering usage also shows up as the standard "wap.cingular" on the bill, and MMS has worked for the past 3 days with no problems. Visual Voicemail continues to work as it always had for me since I updated to 3.0 and used the original 5.0 .ipcc to enable tethering. I just wanted to make sure it would not break before I posted something. YMMV...keep this in mind. The camera icon in messaging did not appear for some reason on my initial re-spring, but it did show up later on (and it has stayed that way). Here's an MMS I just sent to myself for proof: Good luck. (Just extract the .zip file, which was originally a .rar file but I changed it due to MacRumors' file-type restrictions).