(I have no idea if this was previously mentioned. Didn't see any other threads, so if a duplicate, feel free to ignore!)
A fellow going by the name of AzzerUK went into the code in SimCity, managed to turn on the debug mode and figured out how to modify the highways and such outside of the city limits. As well, he was able to remove the disconnection timer and played for as long as he wants. He can't save the city while off the server, but it rather effectively shows that EA and Maxis were relatively full of crap when they stated that calculations for the city are online only.
Pretty amusing, really.