Day 0 jailbreaking tip
Many of you are posting frustrations with inability to install apps from Cydia.
Most of the updates you want, including BiteSMS and SBSettings, utilize another packaged entitled "Mobile Substrate"
Downloading BiteSMS, as an example, will attempt to download BiteSMS, Mobile Substrate, and Safe Substrate. The latter two are part of the same package. You'll see your phone download BiteSMS, get excited, and then disappointed when Mobile Substrate fails to download and the process is aborted.
In the meantime, you've used up very precious bandwidth while downloading BiteSMS and gained nothing for it.
Saurik's servers are getting hit the hardest. That means Mobile Substrate is likely to be the harder part to acquire. Instead of trying to download the apps you want, search Cydia for "Mobile Substrate" and install that first. While it will be difficult to get in, it will save you the time downloading the other tweaks you're interested in if MS fails.
Once that installs, it's much easier to install the tweaks you're specifically chasing.