right I agree with capstonic that no software is like odesk client software. But similar to that translation workplace is good. You check this software from translationtrudy dot com.
This might be a late reply to the original question -- Check out the SaaS service Worksnaps (www_dot_worksnaps_dot_net). It has the exact functionality to track and verify time and work activities. It is a great tool for managing remote contractors. And there are many extra capabilities such as reporting generating, privacy control, integration with 3rd project management software and etc.