Here’s a superb reader tip: DJ Josef Prusa has been using SugarSync to synchronize Native Instruments’ Traktor Pro DJ software, so that he and his brother have their full music collection at the ready at gigs. (Naturally, this same technique means that if one of their MacBooks should die, bro to the rescue!) Not only does music get synced, but playlists, collections, MIDI mappings, and settings do, too. Now, you could use something like the ubiquitous free command line utility rsync to do the same thing, but SugarSync has the advantage of giving you cloud storage, too, so you have an additional backup and always-on access to your files.
Traktor is just one example. You could do the same with any other essential files. Josef also syncs Max/MSP patches for monome, plus a promising-looking, in-progress wifi controller. File sync in SugarSync works across Mac, PC, and now iPhone, Windows Mobile, cell phones, and Android. (One gripe: no Linux support, something DropSync can muster.)
Before this becomes a SugarSync ad, though, I am interested in what other solutions people are using. There are various cloud storage and sync services. SugarSync is fairly unique in providing both true sync/remote access with cloud storage. But maybe you have added your home server to the mix, or found another solution.