You can back everything up with time machine and then restore the time machine backup on the new HDD.
If I just bung the 500gb in can't I just back the main drive up to the 500gb and then take out the main drive and use the 500gb as the new main?
I used a program called CarbonCopyCloner to do exactly that... Adobe apps dont like it but everything else worked perfectly.
The other option, and probably better, is to re-install OSX on the new drive and then at the final stages of installation it asks if you want to migrate any settings and apps from other machines, point it at your old boot drive and it wil do the rest.
Gah, don't respect a silly exclamation pointAs Darryn says, CCC doesn't work well with Adobe applications but SuperDuper! works perfectly. I did exactly what you've done using SuperDuper! and it did the job very well.