Design a two sided business card

We want a cleaner fresher feel to the cards with and interesting and relevant design on the reverse.
Current versions can be provided along with .eps logos and ideas for new design. Please provide examples of previous work or links to sites with relevant content - examples obviously not restricted to business card designs!
Output will be design files that are editable (names, numbers, email) and in final format for print (meet proof requirements etc.).
Deadline is 15th May for completed files following consultation, review of 3-5 strong ideas and final changes.