KeepSync ($30) is based on a great concept: automatically keeping data synced between all your computers and mobile devices by moving it across either your local network or the Internet via company's own online servers. The interface is simple and attractive, and the local network syncing, Internet syncing and sharing (using bandwidth credits purchased from Proxure), and local backup performed as advertised. However, this product still sports a lot of beta-like rough edges.
Said jagged boundaries start small, with minor irritations such as clipped text on the Web site and in dialogs at non-standard display DPI settings. One serious flaw reared its head: The client froze up on one of my testbeds when I accessed the videos section on two separate occasions. I'd also have liked to see operational concepts (a client is needed for every device) explained better, as well as an easier way to access synched files other than through the aforementioned lists.
Despite the nits, KeepSync foretells a future where it'll be easy as pie to keep your data synced across all your devices; Windows Server/Mobile clients are in beta and Mac OS X/iPhone clients are promised. It's useful now, but that will make this a killer app.