I was also suffering from a lame PSN ID. You can't change your ID, but you can create a new one, keep your game saves and still use your primary email.
1. Create a new/dummy email account.
2. Create a new user on the PS3 operating system. This will be the one you will use from now on.
3. Under PSN "account settings" change your PSN account's email address to the new/dummy email address.
- PSN accounts are linked to the PS3 user through the email account.
4. Under file management (I think thats what it is called), press press triangle on the game saves you would still like to use, select "copy" and then select your new user name (new PS3 operating system user name). Repeat as necessary.
5. Under your new user name you can sign up for a new PSN ID.
6. Delete your old PS3 user name if you wish and the corresponding extra game saves.
Hope this helps.

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