Unknown

I swear I've seen a film like Unknown before but I just can't quite put my finger on it.
Liam Neeson stars as Dr Martin Harris, a biotechnologist who has flown to Berlin for an international summit. When he arrives at a hotel with wife Liz (January Jones), he realises he let his briefcase at the airport and jumps in a cab, driven by Gina (Diane Kruger) to get it. The cab crashes on the way to the airport, plunging into a river and knocking Harris out immediately.
When he awakens at a hospital after four days in a coma, Harris discovers another man with his wife. Furthermore, she doesn't remember who he is.
The rest of the film centres on Harris trying to reclaim his identity, with a few large twists thrown in along the way.
I was generally surprised by the film. It is clearly not an original idea, and I'm sure there are umpteen holes in the plot if you search hard enough.
Neeson shows why he is one of the busiest actors in the business, while Kruger proves to be more than handy in support.
Worth a watch, but you've probably seen it done better before.