I used MyBackup. You can download it from the market, you get a 30 day free trail and after that you need to buy it (+-R40) but its worth it. Works on rooted and none rooted phones with a easy to use interface. One problem that I faced is that it did not back up my contacts only those synced with Google but luckily i had a saved .csv contacts file that i just imported to my google account and then synced it with phone. I use GO Launcher and any chances you make in there you will have to back up separately - do this with every app where you have a back up options.
I hope this doesn't put you off of flashing to 2.3.4 but for some reason I cant connect to Kies on my PC, it just continues to say connecting but never does. I absolutely HATE the Kies software so this does not bother me. I will from now on always flash new/updated firmware via ODIN.
Swift which case did you order? Also found this case
http://www.expansys.co.za/case-mate-samsung-galaxy-s-ii-tough-cases-black-218855/ if you need your phone to be like a tank, prolly made for construction workers, there are reviews on Youtube of this case and I must say it is very impressive, blows all other cases away if you can stand the added width it adds.