Cases for Handheld systems

[Rhinestone]

Hello everyone! First of all, I want to thank you all for this great community. I'm not very active and participant, but I visit the site and forums quite regularly and it have helped me a lot.
Now the question is: I have a Game Boy Color system, and I pretend to get more handhelds in my collection (principally the GBA SP and a Nokia N-Gage), but I don't have the original box, so I've been thinking about using some cases. I've tried with a VHS case or even Sega MegaDrive/Genesis cases, but they're not thick enough.
Anyone has tried/done the same? Is there any type of cases you could recommend? 

[Arseen]

I  believe DVD cases can be found up to 55mm or so thick.

[wiggy]

The ol' double UGC works well

[Rhinestone]

Thank you for the suggestions guys, but I've found the solution: Double VHS Cases 
Today I visited my local second-hand store and found a sealed copy of a Double VHS with two Disney movies, so I just grabbed it.  The case is thick enough to store a game boy handheld, so it's perfect!