Whoa. Cool.

The version on creatures would probably say "When this creature dies".

The mechanic does have the drawback that you really need something card-shaped to stick in a pile with your lands. Multiverse will happily create them - Land :D - but if you don't get one in boosters, it'll be fiddly using glass beads or pennies to indicate if they're tapped. Most of the time you can pile them with your untapped lands, though even that would be somewhat hard to read from across the table, but it causes more of a problem if your only untapped land is a token.

Aha, but that is why it exiles you see? When something dies and you get a token, you have to keep the dead creature in the graveyard because thats accessible space and something could care about it. But since it's exiled, you can use the card itself as the land token. (I would just turn it over)

Oh. Of course. Beautifully done.

awesome idea