I loved him in "Due South" as the mysteriously manufactured Chicago cop-sidekick to Mountie Benton Fraser. He was funny and gritty at the same time, and despite replacing a favourite actor he did a fabulous job of replicating the "same" character.
He was barely recognizable in "Tin Man" partly because his bad guy was so bad. He was a bright spot in a sometimes marginal production.
He again brings his uber bad guy to "24" this year and makes the mistake of engaging Jack Bauer in clandestine activities. To date, that has not been a healthy or long term pursuit for Jack's opponents, but its a paycheque. I'm looking forward to Callum's characterization and how it all ties in to the big picture.
I am really looking forward to his movie reunion with Paul Gross (aka "Benton Fraser") in the Comedy/Western "Gunless" this April. The previews look great. The premise looks different and entertaining.
There is no doubt Callum Keith Rennie is a very versatile and underutilized actor indeed. I look forward to more of his creations...