[8_hours_ago]

Give them a computer and some resources. Let them work on a problem for a few hours. Then have a discussion with them about how they approached the problem, any limitations of their implementation, and what they would do if they had more time.

I don't see how whiteboard-style coding interviews can scale any better than that approach.

[daxfohl]

The thing I don't like about whiteboard: A solid candidate that has a bug near the top of a function ends up looking sloppy because whiteboards don't have "insert". The same candidate making the same bug at the bottom of the function can just erase a closing brace and continue looking marvelous. It's very arbitrary I think.

[nitrogen]

Possible solution: leave room at the top of the whiteboard and between some lines for erasing and rewriting sections.

[daxfohl]

Another option would be to write the program in BASIC, with line numbers.