Custom icons (or pre-made icons) for custom categories

Cha-Ching Touch currently has well-illustrated icons representing default transaction types. For example, the infant/baby category has a nice little bottle icon. This is very handy and makes the app feel very polished. However, if a user creates his/her own categories, no such icons are available.
I suggest including a collection of perhaps 15 additional icons with which a user could customize the appearance of his/her custom categories so that they are no longer represented by a [ ] icon that implies a lack of polish.