Here are some tools that have improved my productivity. You may find them useful as well.

• Do.com for managing tasks & projects
• iPhone, especially tethering my MacBook Air
• Google Reader & Twitter for keeping up-to-date on news & opinion
• MailChimp for e-mail marketing & communications
• Gmail with labels & filters
• Mint for managing personal finances
• Picasa for organizing, editing and sharing photos
• Freshbooks for invoicing
• WordPress for blogging and for the framework for non-blog web sites.
• TextMate for coding
• Acrobat Professional for working with PDFs