Accountancy

Neat receipts [$139] An accountancy app coupled with a receipt/doc/card scanner 

http://www.neatco.com/

Collaboration

Google apps [free] Hosted office suite 

http://www.google.com/apps/

Slideshare [free] hosted powerpoint sharing

http://www.slideshare.net

DimDim [free/$] Screen share collaboration software

http://www.dimdim.com/products/dimdim-video-tour.html

http://www.twiddla.com/ 

Lovelycharts [free] online hosted flowchart application

http://lovelycharts.com/index.php?page=tour

Operational

37 signals [$12/mo+] basecamp and highrise, project and contact management

http://www.37signals.com

busy sync [$40] universal calendar synchronization between google calendar/iCal

http://www.busymac.com

Netsuite [$120/mo++] Full company wide hosted Enterprise Resource Planning software  

http://www.netsuite.com

Time Capsule [$300/500GB] Automatic backup solution + WiFi Router with guest networking

http://www.apple.com/timecapsule/

mobileMe [$100/yr] apple's version of exchange. Contact/ calendar sync mobile disk access

http://www.me.com

WordPress [free/$] online blog creation 

http://en.wordpress.com/features/

Google Analytics [free] Domain statistics tracking website traffic monitoring

https://www.google.com/analytics

Telecom 

Virtual: Virtual PBX [$40/mo+] Virtual PBX phone routing system 

http://www.virtualpbx.com

Real: Packet 8 [$99/phone, $40/mo] Routes calls to any IP phone.

http://www.packet8.net/

Grand Central [free] One number that rings all your phones

http://www.grandcentral.com/

Legal

TechStars legal forms [free] All the basic forms you could ever want - from The Foundry

http://www.techstars.org/2009/02/07/techstars-model-seed-funding-documents/

PR/Marketing

twitter [free] Best PR Available (@comcastcares, @delloutlet)

http://www.twitter.com

TweetDeck [free] twitter monioring tool. Take it a step further with radian6 [$$$] readwriteweb

http://www.tweetdeck.com

Development

Github [free] parallel development through social coding

http://github.com/