[ayers]

You could always send a candidate a simple(or complex, depends on what you are looking for) task that they need to complete a working solution for. This could be more beneficial than already prepared code samples.

1: You will know the time frame in which it took the candidate to write the solution.

2: You are setting out the parameters for the task and can choose an area(specific skills) that you are particularly interested in testing knowledge for.

I know a lot of companies do this as a standard practice.