Start-ups are fun, exciting, scary and should be on everyone's bucklist (at least once). It's helps build endurance, a thick skin, some real street smarts and a real appreciation for all the little success (and horror) stories around us. A key concept is to keep things moving forward, to build momentum. Each step along the way, how miniscule it may seem, whether an email, a phone call, a note, or a line of code, all in aggregation help contribute to the success.
Thus from day one simplicity and productivity is critical. I've put together a list of web services, apps or whatever you want to call them, that I believe or at least have experienced to be essential for any and every startup to help maintain focus, communication, simplicity and productivity. In no particular order here they are.
Basecamp. From the clever team at 37signals, Basecamp is a brilliant project management application. Effective for managing and tracking projects with disparate teams, or collaboratively with clients this is a must.
Google Apps. This is an obvious one but the easiest and most inexpensive way to get things real with email, basic document management, collaboration, wiki etc.
Pivotal Tracker. Great tool for agile software development teams for tracking and managing projects, requests, bugs. Also extends well into managing support requests.
Hootsuite. Every startup needs to manage their social presence. Hootsuite is a good standard to launch with.
Campaign Monitor. Great design, intuitive and feature rich, Campaign Monitor is by far my favorite service for managing subscriptions, email lists, newsletters and email outreach.
Campfire. Another beauty from the 37Signals team and a must for any distributed team. Think of campfire as a group chat with persistence. It helps build team dynamics across globally scattered teams, and general chatter to keep people connected. We've found it useful even when on vacation as a great place to check in a scroll through the daily logs.
Dropbox. File sharing can be a real nightmare. Dropbox makes it easy and a life saver when on the road. New team options makes it even better.
There you go. All are very cost effective, and will make your teams much more productive and engaged.