Nice post from Don Reisinger at Webware.com - with succinct run down of useful web applications for small businesses (or those with no budget):
Basecamp - Project Management
Evernote – Add notes, post-its, media everything includes handwriting recognition – one of my personal favourites
FreshBooks – for online invoicing
Presently – Twitter for business
Shoeboxed – US service for scanning your receipts for filing Tax submissions etc – Possible very useful for UK consumers in future as Don mention’s they’re tying into Freshbooks and Evernote