Barack Obama topped the list of search terms on mobile search engines in Q1, while his erstwhile rival for the Democratic presidential nomination Hillary Clinton came in at number 14. More than half (53%) of mobile Web traffic is driven by on-deck carrier portals, with AT&T accounting for nearly a third of that traffic.

These figures come from the inaugural Crisp Wireless Index (CWI), a new quarterly barometer of traffic across some 200 sites in the Crisp Network that see more than 14 million unique visitors per quarter.

According to the CWI data, users are revisiting the same sites more often, as visits per unique visitor increased 32% from 4Q07 to 1Q08. Sites drawing the highest percentages of visits per unique are in the Women's Lifestyle, Youth and Television & Entertainment categories.

To get more detailed metrics in a number of related topics, you can register to receive quarterly updates to the Crisp Wireless Index here.