I'm not sure what making the phone in China and adding other repos have in common other than it appears the one mentioned above may be from HK. Be that as it may, there are a few suspect repos included in Cydia. However that is the risk I decided to take to have Slingbox on 3g. Besides the standard stuff needed for the JB, I only added tricker3G which added mobile substrate. Beyond that if I can do a hack thats worth it without using Cydia, I'm up for finding the tools and giving it a try. I once tricked a phone out so much, I realized that the primary purpose, making and receiving phone calls no longer worked, but I could browse the internet LOL
I have a 2G and i have the newest swirly MMS which is actually a real good program but it costs money. However, i also have the MMS capabilty doing it the exact same way it was meant to be used on 3G and the new 3G S using a program in Cydia. I have the camera icon next to my message typer and ive sent and recived already. All the others for the most part cant do that yet because AT&T is screrwing them over, but i can.....and im not supposed to be able to use that at all with my 2G because Steve Jobs didnt think us 2G users were worthy i guess.
IMO jailbreaking is awesome while everybody else who dont do it is whining and refuse to do it for whatever reason. Some claim lag time, but right now mine is actually faster in load ups than it was with 2.2....those are the wusses im talking about.