I've migrated a few times around.. For this sort of thing, there's a dimension of OSX that really outshines Windows.
I've found that I can perfectly boot any intel mac off of any other intel mac's hard drive. I haven't yet found exceptions. I had my macbook in for servicing for a while and put the hard drive in a USB enclosure and booted my mac pro off that drive, everything worked insanely well. You have many options, but you DO NOT need special other applications. The OSX install disc has everything you could need, and really, if your old hard drive is good enough, then you don't need software at all.
Drop in old drive
You could just move your old mac's hard drive in to the new machine. Though, that probably isn't what you really want.
"Restore" your old drive to the new
Just do this:
Put your old mac drive in a USB enclosure and boot your new machine off the OSX install disc..
Use the "Disk Utility" from within the installer to "restore" your old drive on to a new/fresh partition on the new drive. The restore will copy over everything and fit it accordingly. Everything will be exactly as it was, on your new drive.
Disconnect the USB/old drive, run on the new one for a bit and verify everything is perfect
Different OSX Versions
Now, if you're in to different versions of OSX and whatnot, you could copy everything from /Applications to the new machine and copy your entire user's home directory too /Users/[username] - I believe that'll catch basically everything. I think some stuff could also be somewhere in /Library/Application Support/ - but really, I'd just do the restore option I suggested before.
This is an area where I really adore OSX.