There are a couple of tools for those ultralight startups out there. Here is my list (as of now):
IDEATION AND BIZ PLANS
http://bit.ly/xuGwbN : How To NOT Write A Business Plan.
http://launchrock.com/ : LaunchRock helps you setup a social launching soon page in minutes.
http://www.mockupeverything.com/ : A lightweight app to make photorealistic mockups on real objects. Choose a template, upload your design, mock it up in 3D, save your image. Showcase what your design looks like in the real world! Everything from apparel, hats, posters, business cards, billboards, iphones, ipads, and just about everything else. Made by Go Media, so you know it will be good!
PRESENTING and COORDINATING
http://prezi.com/ : Prezi is a cloud-based presentation software that opens up a new world between whiteboards and slides. The zoomable canvas makes it fun to explore ideas and the connections between them. The result: visually captivating presentations that lead your audience down a path of discovery.
http://asana.com/ : Asana is an effort to re-imagine how teams get things done. We’re building the modern way to work together, through a web application that connects everyone with what’s going on, their shared priorities, and who owns each part of the effort.
http://angel.co/ : AngelList is a community of startups—started by the dudes who do Venture Hacks.
http://bit.ly/zXrrLP : Dividing Equity Between Founders and Investors
https://www.elance.com/ : Hire expert programmers, designers, writers, translators, marketers, researchers and admin contractors with tested skills
http://www.stackmob.com/ : StackMob's mobile platform helps developers create a mobile business by letting them easily build, deploy and grow full-featured applications
http://www.heroku.com/ : Offers a solution to deploy and host rails applications with git