I di exactly this. I used CarbonCopy since Disk Utility failed, as did SuperDuper.
Works now for me and only takes about 20 minutes.
I have SL 10.6.3 on my Mini9
I also have iPhoto, iTunes, Office 2008, iWork09 etc.
I run Mail, Office, iPhoto, Itunes and iWork from my SDHC, using Symbolic linker - no problems.
I have 2Gb of free space on my SSD
- and I could get more if I moved some of the library to the SDHC
My only problem is a dodgy Wireless card that sometimes requires me to reboot and the ~Sleep issue, that causes a crash every time I wake it up - usually within about 10 minutes.