Instead of a level-based xp payout for new areas visited, maybe a low, flat rate reward could be implemented? I never did understand why a higher level player got more than a lower level player in this particular situation.
I like that xp is graduated for higher level players...since they have to earn so much more xp than a lower leveled player, it's a nice feature of the game that many actions take this into account and it doesn't take until infinity for a higher level player to get to the next level while lower level players are zipping through the ranks. I think this is one of the best balanced leveling games that I've seen thus far, and kudos to the devs. Please don't change this aspect of the game. Keep xp earning based the ratios of the levels you are at.
Shame it stops at 500, since it seems like with the rate of growth of the world, that we could quickly be over 1000 streets in 6months...unless there is some planned limit to the size of the Glitch world. Maybe reconsider a flat xp award after 500 which would diminish it's value the higher you level, but still is some reward for exploring...