The two dollar bill has many oddities. The fact that it is near obsolete is only one of them. Here are a few of the rest:

1. The denomination.
By today's standards, in the USA, two dollars is an odd denomination. We're used to ones, fives, tens, etc. But a two? They're now a rarity to come across, so we look at them differently.

2. Bad luck?
For a while, two dollar bills were commonly used in voter payoffs and betting. These activities garnered a reputation of bad luck for the poor bills. This tradition is still held on to by some. To counteract the 'hex', these people tear a corner off of the deuces they come in contact with. For some reason, that's supposed to ward off the evil.

3. 'Whore note'.
That's right. Back before inflation made prices soar, two dollars was a good price for a bit of action. This ill repute lended itself to the nickname and to a stigma that lasted long after the price was out of date. This prostitution connection also has kept Jefferson from being on other denominations. He was considered for the Susan B. Anthony dollar, but this was one of the reasons that kept his face from being on it.

4. The artwork.
The etch work done on the bill is simply exquisite. It is an beautiful representation of "The Signing of the Declaration of Independence" by John Trumbull. But it is just that. A representation. It is not accurate. One of the key elements of original piece was the tension between Adams and Jefferson. This was shown by Jefferson's foot stepping on Adams'. A slight detail. But one that is missing from the two dollar bill.