I had some experience with DeltaCopy which is a front end to rsync (cygwin).
It was OK, but I had problems synchronizing some Cyrillic files, and honestly I don't think it is the easiest tool to use...
I wanted something simpler.
I ended up to play with FreeFileSync, an open source application hosted on SourceForge.
I was amazed by the quality of this tool. It is quite efficient and easy to use.
The interface is available in many languages, it is intuitive and has very interesting options. The help is very comprehensive. The tool is well polished and has professional features.
It supports larges files, it has a 64 bits version, it supports synchronization of a huge amount of files and it supports very deep paths. You can use it to backup folders on a network drive. You can mirror, update, and customize the way you want to synchronize folders. The synchronization operation is very fast. You can compare files using the combination of timestamp and size or by content. (I guess md5 is used to compare). If you wish, you can save your sync configuration and use it later.
There are binaries available for Ubuntu 10.04, however I haven't tried this version yet.
It is a matter of minutes to get used to the tool and to get your job done.
If you need to synchronize folders in a few clicks, and you want a software that is easy to understand FreeFileSync is the tool you need!