I'm looking to advertise our online time tracking software application:

Web based time tracking software - Timesheets and Time keepting application - 1time

we have a google adwords campaign running and i'm now looking for some other avenues for advertising.

Our target market is project based service companies or any company that has a need to record time. e.g. Creative companies, accountants, software, architects, consultants etc.. Usually SMEs

I have a list of a few sites that may have a large amount of our target market. At the moment i'm looking at design companies as they seem to be the most active users so far.

I need to get the best value for my buck as it where so..

Any recommendations ?