Kaa-ching is nowadays on various forums and irc the alias for Klaas van Gend.
Klaas originally always used kvangend as login - until he realized that 'vangend' means catching in his native language, Dutch.
For about a day, he changed his nickname to kcatching, and then switched over to kaa-ching. It looks better and also has some bearing on his job (He works in the sales organization of [MontaVista])
Several people already confused his new nickname to be Chinese, which of course adds to the fun.
Klaas is the lead developer for the open source user land project to bring support for UMTS to Linux: umtsmon.
Professionally, he has been spending significant effort in promoting embedded Linux and more specifically real time Linux.
He also is a board member of the NLUUG and is one of the co-organizers of the Embedded Linux Conference Europe.