My Palm m505's 8MB of RAM has been maxed out for quite some time. After surveying the crop of 16MB Palm OS devices currenly on the market, I'm hard-pressed to find a deal like the one available on the CompUSA web site (note: you can't get this price in their stores). The Palm m515, which retails for $349 ($299 after a $50 mail-in rebate), is available from CompUSA for the "web-only" price of $299 before the mail-in rebate. After the $50 mail-in rebate, the final price is only $249.
That's half the price of a Tungsten T. I don't think Palm OS 5 is going to be a must-have for at least a year or so. Plus, I don't really like the Tungsten T's sliding Graffiti area.