Powerpoint! The next installment of web as desktop is Thumbstacks, an online presentation builder and, um, presenter.
Create and edit slides online with Word-like rich-text editing controls and with images and drawings from anywhere on the web. Launch and view your presentation right from the Thumbstacks site and edit it from any internet-connected computer. Thumbstacks is [...]

ThinkFree Office Online lets you open, edit, create, and save Microsoft Office documents (Word, PowerPoint, and Excel) from any browser for, just as you thought, free. ThinkFree Office Online also boasts the ability to:

Post documents directly to your blog without any conversion
Create powerful Web presentations using a familiar interface
Convert your existing documents to PDF format

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