iPhone Official unlocking
Starting at $50
Price depends on what carrier phone is locked to.
Unlike the software/gevey unlock this is considered a official unlock (which is why it can be more expensive). Updates and restores will not re-lock them like normal software unlocks.
If you see any issues where a update does lock them I cannot be held accountable but with this method you should not have any problems with this happening.

iPhone Unofficial Unlocking
iPhone 2G/3G/3GS/4 Unlock/Fix: $50
Update/Restore: $20
Gevey Sim for iPhone 4S/5: $50-$85
Just activation/Jailbreak: $20
When software/gevey Unlocked the iPhones cannot be updated/restored in iTunes. If they are updated they will relock and may not be able to be unlocked again.
It is highly recommended to have a backup of your iPhone in iTunes  before bringing it in just in case a restore is needed so that you can restore your stuff with iTunes after.

Blackberry (excluding new BB10's) 
$35 
Androids 
$50-$75