The inspiration for this was the metaballs tutorial in TrueSpace. The tube was a booleaned cylinder with a glass texture, the ball was given rubber properties. If you want to see the resulting huge and pointless animation then click on my name below and send me and email and I'll give you the url.

(Okay, I know it's not terribly realistic and it's floating above the desk, but at the time, reality wasn't really important to me)