Wikicalc deserves some props for being a groovy open source spreadsheet wiki that's very decent for it's price, and works through some crucial bits of excel, so as to retain basic formulas and such.
With jot.com going to google.com last week there's another bunch of kids in the same playgroundsure to bring good attention to the arena where more transparent business practices can be developed, standardized, and optimized. Their product is sleek AJAX based and with calendar and location parsing technology built in this is one another slick development for the google folks.
And so that brings it around to the c-village 'hood skool. - charlottesville.jot.com - starting out with some of the non-general stuff, and working towards the line item morsels.