I've been trying to find this guy for a while... Looks like he's at FSV Optik Rathenow. The team's website is under construction, but here's a fansite page showing him, some info and a photo of him apparently wearing an old Tony Sanneh Hertha jersey. http://zeus.fh-brandenburg.de/~lorenz/Optik-HP/Kayser.htm It's a fourth-division club. He is listed as having started at striker in the team's latest match on the official club website. He was born in 1983. http://www.optik-rathenow.de/Willkommen/Oberliga/oberliga.html
Joined Optik Rathenow in January 2003, previously played for a college in Seattle. The team is on rank 6 in its D4 division, apparently their best start ever.