If you're backup up your apps, data, sms and mms with ROM manager, you can extract individual items with this tool called AppExtractor. AppExtractor is compatible with ClockworkMod Recovery 5 backups as well as backups created by previous versions of ClockworkMod Recovery.
There's a FREE version and a paid version. The FREE version limits you to restoring 5 apps at a time while the full version (an unlock key app) removes this limitation and allows you to receive future updates as well. Do try out the app below and if you love it, get the paid version for $1.99 only.
AppExtractor (FREE) - Android Market