First off: FreeNX. Upto now, I used VNC to control the Ubuntu desktop of Sootball (when it's turned on) from Calcifer. However, VNC is pretty slow to update the screen. A colleague of mine demonstrated using FreeNX to log in on the Ubuntu machine of his parents over a modest ADSL line -- and it was screaming fast -- much faster than the VNC speeds I get over my LAN.
NX is a very efficient protocol, and it tunnels over SSH. Using FreeNX, I can use Sootball as if I'm directly logged on to it. Of course, that speeds up things tremendously. There's also an NX client for Windows machines, so if you use Windows as your main workhorse but need to do stuff on a Linux machine, FreeNX is your best choice.
Unfortunately, there's no NX server software for Windows -- I'd love to use it for taking over Jiji. Alas, in that case, I'm stuck using VNC.
Secondly, SoapUI, a webservices testing tool. I've used SoapUI 1.something to test calling a webservice -- pretty cool stuff if you're writing a webservice and want to see what happens if you do an actual call. But last week I upgraded to the latest version (2.5), because the software I was working on also had to call a webservice.
Using the WSDL as input, SoapUI can generate editable requests that you can fire off at the webservice. But using that same WSDL, the newest version of SoapUI can also generate a webservice! You can define one or more response messages, and using either scripting or XPath queries, you can make the response sent back dependant on the request received.
This is a great tool if you're on either side of a webservice, and only have a WSDL to go on.