So, a new tent. The REI Chrysalis, your first candidate, sells for $159 (www.rei.com), weighs just over three pounds, and has enough room for two in a pinch. I used one a while back and I must say it's a very fine tent for the money. A little wiggly in the wind, but not bad, and certainly up to the task of everyday three-season backpacking. Kelty's Teton 2 is a little cheaper ($120; www.kelty.com) but is also a pound heavier. Amazingly, both tents are self-supporting (although they must of course be guyed out to ensure the wind doesn't blow them away). A few years ago you had to buy a two-pole, stake-supported tent to get that kind of weight savings.
You still can buy that style, however, and the weight savings are even greater. Mountain Hardwear, for instance, has a new one-person tent called the Skypoint 1 CF. It has hoop poles at the head and foot, and stakes at each end tension the whole thing. It weighs a ridiculously light two pounds, nine ounces due to its single-wall construction and poles made of a light alloy called Scandium. Alas, price is $220 (www.mountainhardwear.com). Plus, its single-wall construction is designed to vent well to keep condensation to a minimum, but if you're mostly an East Coast backpacker, it might not work as well as it does here in the drier West.
So I'd probably go with the Chrysalis, and enjoy my suddenly lighter pack.
Read "Friendly Confines" for a look at more solo shelters.