Did I just buy my last Palm smartphone? My aging Treo 600 — yes, I hear your snickers already — died at SXSW, and I picked up a cheap Centro to replace it at a Sprint store. (A tip: Skip the $50 rebate and pay $149 instead of $99; the monthly data plan will be less expensive.) Chairman Jon Rubinstein is revamping the company's hardware and software, but does he have enough time? Until the former Apple exec's inventions hit the market, the company has to make do on Centro sales, which swell its unit sales but hit its profit margins. Palm sold a record 833,000 phones in the most recent quarter, but its $312 million in sales came in below Wall Street's hopes. For what it's worth, I love the Centro; if it hadn't locked up at just the wrong moment, I would have beaten Mashable's Pete Cashmore with his iPhone in a text-messaging duel.