Pasadena-based Idealab, the startup incubator run by Bill Gross, has made another external investment in a company, funding London-based Top10. Top10 operates a service which allows users to create their own "best of" lists in a social way. Top10 said today that it raised $3.5M, in a round led by Accel Partners, which also included Idealab, Founder Collective, Forward Venture Partners, and Shakil Khan. The investment looks to be the farthest venture, geographically, for Idealab, which recently booted up new efforts to invest in firms not directly incubated in the company's offices. Top10 competes with such local companies as FindTheBest, the startup in Santa Barbara led by former Doubleclick founder Kevin O'Connor, which ranks the best of many items; and Ranker, the top 10 ranking firm led by Clark Benson.