GoodSync File Synchronizer

Geek.com does a good job of reviewing software, so I am going based upon their recommendation of GoodSync.

"GoodSync uses an innovative synchronization algorithm to synchronize your data between desktop PCs, laptops, USB drives and more. GoodSync combines bulletproof reliability with an extremely easy to use interface.

Most synchronization software claim to synchronize your files, but many simply copy from place to place. GoodSync offers true bi-directional synchronization, which prevents deletion of files and data loss."
- GoodSync

[via Geek.com]