One of the themes that Senior Editor Robert Strohmeyer found at the Web 2.0 Expo in San Francisco was a variety of collaborative business tools. Springnote lets you work with teams on notes, calendars, documents and other information. With Hylighter, you can let colleagues mark up your document while retaining control of the original. Expresso, allows online collaborative sharing of Excel spreadsheets. And OpenACircle is a conferencing tool that lets up to 12 people meet and share documents in real time.