I rather like the idea of grouping Bitcoin units by 10,000 as others have said.

It fits in well with Bitcoin's design of 8 decimal places in total.

Grouping by 4 decimal places makes sense here, because 8 decimal places fits cleanly into two groups of 4.

Japanese culture already uses grouping by 4 decimal places: man, oku, chou, kei.  (Maybe this is why Satoshi chose to divide Bitcoin into 8 decimal places, and not 6 or 9, as a Western designer might have done?)

Chinese culture also groups by 4, and we all know how important China is to Bitcoin.

And, we already have a unit for 10,000 BTC, the Pizza (named after the first successful real-world transaction), so this is a smooth progression of units.

10,000 Satoshi = 1 ?

10,000 ? = 1 BTC

10,000 BTC = 1 Pizza

OK, enough rambling, here are my nominations for the "?" unit:

Nakamoto (goes with Satoshi)

Finney (memorable, and a tribute)

Others have already mentioned these, but I agree with them.

Josh

I do not want to sound ignorant but what is the "big wall?"

its to bad i sold shouldn't of been playing with triggers

I have some play btc left

and still very bullish!  

Can someone say how high the wall was to begin with exactly (from this one seller)?  Didn't catch it.

Now why is coinbase much higher than anyone else?

Yes...  there's still a freaking 5k wall.

China waking up.

Is there a reason no one wants to sell coins on Stamp?? There's like only 5k coins for sale up to $380. But there's over 20k on Gox.