My Votes are as below. Most of my choices are based on my daily uses.
Audio - Last.fm
http://www.last.fm/ Social music discovery and listening tool. Listen to full tracks, and create stations around artists you like
Commerce - Elance
http://www.elance.com
Elance is an online workplace where businesses connect with qualified professionals to get work done, facilitating the entire process from hiring to collaboration to payment. At a time when small businesses are looking for more flexibility in hiring and resource management and many professionals are looking to contract work and freelancing as a career, Elance provides the complete solution--all in a secure, easy-to-use web application.
Elance is an online workplace where businesses connect with qualified professionals to get work done, facilitating the entire process from hiring to collaboration to payment. At a time when small businesses are looking for more flexibility in hiring and resource management and many professionals are looking to contract work and freelancing as a career, Elance provides the complete solution--all in a secure, easy-to-use web application.
Communication - Gmail
http://www.gmail.com/ Google's Web based e-mail, which currently offers users in excess of 7 GB of free storage.
Instrastructure & Storage - Amazon Web Services
http://www.amazon.com/gp/browse.html/ Comprised of five different services that help power many of today's biggest Web services, including S3 storage and EC2 elastic cloud computing.
Location-based Services- Google Maps
http://maps.google.com Google's free online maps service. It provides driving directions, traffic, and search results for local businesses.
Photo & Video - Flickr
http://www.flickr.com/ Yahoo's photo and video sharing community. Users can upload and organize their photos, then share them with others.
Productivity - Google Docs
http://www.google.com/docs A collection of online office programs including a word processor, spreadsheet tool, and a presentation maker.
Search & References - Technorati
http://www.technorati.com Tracks stories around the Web and organizes them on a news page. It also gives each post authority based on how many other blogs are linking to it.
Social networking & Publishing - LinkedIn
http://www.linkedin.com/ An online directory of people used both for business and social networking