The account you buy ML for (the apple ID you sign in with) is what the OS will be tied to. But if you have OSX on a flash drive after downloading it, it won't matter
Though if you want to keep programs but wipe out everything else, you can just create a new account.
Go to Apple > System Preferences > Users and Groups
Click the unlock button and enter password (press return if there is none)
Click the plus button down in the bottom left corner of the white column.
Enter in Your user name, the short name you wnat for your account (this is what your user folder will be called), password, verify password, and enter in a hint. Make sure the account is set to administrator.
Log out, and select the user you just created. Go back into users and groups
Unlock then click on the account you don't want
Click the minus button and select Remove home folder (it is the bottom option). Don't select secure erase. As you use the machine and as the machine works, it will overwrite the deleted account over time.
Enjoy your new account. All system settings are stored (mostly) inside of the user account.Edited by Lord Xeb - 3/19/13 at 6:41am