The signs are everywhere: American automakers are on the mend. Free of any bailout stigma, Ford is leading the pack, with compelling cars and trucks delivering massive profits. One step behind, General Motors has emerged from bankruptcy as a leaner, nimbler company, with several new models that are scoring well with critics and consumers. And Chrysler has allied with Italy's Fiat to revamp its aging car lineup. Whether Ford can sustain its momentum, and whether GM and Chrysler can thrive again, remains to be seen. What is clear is that Detroit's Big Three are raising their game. These 10 models are proof.

Athletes and cars aren't the only ones with a need for speed. Animals, astrophysicists and riders of roller coasters also pursue jaw-dropping velocities. Here are some of the fastest things in the world.