If you want something truly, permanent, though, you can get a commemorative gold-plated bitcoin for... the grand sum of $7.88.
List of dead and worthless cryptocurrencies
Deadcoins (by matixmatix) is a list of, well, dead coins: the Bitcoin-esque cryptocurrencies that failed to take off, which were scams or experiments, or which otherwise are now deceased. Or, perhaps they're all dead, the new Bitcoin boom notwithstanding. Speaking of which, Bitcoin is dead, long live Bitcoin.