Macfusion
Unfortunately I've lost data using Macfusion when TextMate beachballs looking through the remote filesystem. ForkLife has a ridiculous amount of awesome, such as easily creating 'synclets', standalone app files that will sync directories when you run them, and 'droplets' which are apps that you can drop a file onto to upload it to a specific remote location. You can mount any remote directory as a local volume (a la MacFusion but more powerful). It really makes working with remote files as transparent as working with them locally, you can transfer or sync remote directories against each other with a bunch of options (such as includes/exclude by regex filter & more) and it has a great visual diff/merge tool also. I'm usually all for open source but this program saves me so much time that using anything else would cost me way more than $30. It's a one-man-shop (like a lot of the best software ;) ) so I feel good about giving him my support.
Brandon