Today's stable release of Mozilla Firefox 22 (Windows, Mac, Linux, Android) includes a variety of back-end technical updates and relatively minor tweaks (to be honest, the word-wrapping of plain-text files is the most relevant to me).
The most notable news is Firefox's new default support for WebRTC (the RTC stands for real-time communication), a set of API components that allows developers to create browser-to-browser applications without plug-ins. WebRTC was developed by Google for Chrome and open-sourced back in 2011, so Google Chrome (Windows, Mac, Android) of course supports it as well.
In real terms, WebRTC enables features such as videochat, VoIP calling, and peer-to-peer (P2P) file-sharing, all within the browser. (Seth Rosenblatt has more info about Firefox and WebRTC in a news article from today.) One such service that already exists, powered by WebRTC, is a P2P Web client called Sharefest. Located at http://www.sharefest.me/, the service lets you drag and drop files onto your (WebRTC-compliant) Web browser to create links that can be shared with friends or the entire world.
As long as your computer is running and the file exists, anyone with the link can download the file from the sharing computer using a "mesh network similar to BitTorrent," according to the official Peer5 project page on GitHub. Sure, you could use Dropbox, YouSendIt, or even BitTorrent sync to do the same thing, but with Sharefest there's no extra software to install; no account registration; there's no centrally located server on which file delivery depends. And once other users download the file, they can expand the network as well, providing additional peer-sharing power.
To test out the receiving end of Sharefest, try this link: http://www.sharefest.me/9934032a. That should direct you to download the Download App installer file (titled "DownloadApp_1_1_0_112_Setup.exe"), serving directly from my Windows 7 work machine in San Francisco. Let's see if the file stays available when my computer is sleeping ...