Looks like there may be a fix for you 3G kids with the OS4 upgrade... LINK
In the meantime, this is always good for a laugh...
http://www.youtube.com/watch?v=Pdk2cJpSXLg
...and one more piece of second-hand info: If you turn off "Spotlight Search" in the General Settings, that should make OS4 run faster on a 3G phone.
Good thing I'm still running the original OS! ::Banana::