Honestly it is my wallet....which I rarely think about. The truth is that not only does it serve it's primary purpose...as a wallet...but if you get the right one it can serve many more functions as well. Card to wallet(most common) a peek(the next most common way to gaff a wallet) indexes, switches, organizing other slim and small gaffs. If you can dream it up you can find a way to gaff a wallet to facilitate your needs.
The wallet I currently use has two main features, a peek and a CTW, but also has slots for indexes. I don't use the indexes much but they are perfect for carrying my wow gimmick, ungimmicked wow sleeve, a small packet of loops, Business cards for mentalism effects including a close up confabulation routine. If I walk out of the house with a deck of cards and my wallet I am prepared to go in a few different directions with my closeup magic. Either standard fare card conjuring, or mentalism/pk depending on the mood of the situation or what my spectators seem interested in seeing.