Imagine our surprise when, upon firing up Sprint's Galaxy Tab 2 10.1 earlier today for some routine app updates, we saw the 4G logo light up (!) for the first time ever. Yes, ladies and gentlemen, it appears that sometime in the past few days, Sprint's finally deigned to flick the LTE switch in a significant market -- namely beautiful San Francisco. We immediately grabbed our Optimus G and EVO 4G LTE review units and hopped in the car for some quick nearby tests. The verdict? We found pockets of LTE in Potrero Hill and SoMa, and nothing but CDMA in the Mission District -- that's two out of the three neighborhoods we checked. Speeds reached peaks of 16.7Mbps down and 9.4Mbps up with full signal but performance varied wildly, even block to block. Sprint had already enabled LTE in parts of Silicon Valley and had marked the city by the bay for one of its upcoming rollouts. Do you use Sprint and live in SF? Hit the comments and let us know if you're enjoying the sweet nectar of LTE in your area.