Michael T. Weiss (The Pretender) - Ideally, he shows up for one episode as Jarod Einstein, solves a major technical problem and then disappears never to be heard from again.
Tom Baker (Dr. Who) - The first time we see him he pops out of a phone booth at the back of Cafe Diem followed by Sony's Aibo. He knows absolutely everything and teaches Warp Dimension Physics at Eureka High.
Dwight Schultz (Star Trek: TNG) - Most people know and love Dwight for his role as Howling Mad Murdoch, but I think his tortured Reg Barclay would work well on Eureka.
Christopher Walken - That dude scares the crap out of me. I think Evil Scientist is right up his alley.
Rebecca Romijn (X-Men) - She can scatter my atoms any day.
Jeri Ryan (Star Trek Voyager) - You know you want to see her back in that Borg outfit!!!
I've gone through kidney failure twice. The first time in 2000, my mother donated a kidney; and again in 2008, I'm on dialysis waiting for a breakthrough in immuno-suppression medicines before seeking a new kidney.