I've used it to cover the thread on a bead head between the hackle and the bead. Takes only a tiny tiny amount but it really cleans up the head of the fly.

It could also be used for an optional thorax on midges like the one at:

[url=http://www.flyanglersonline.com/flytying/fotw2/071700fotw.html:cbd25]http://www.flyanglersonline.com/flytying/fotw2/071700fotw.html[/url:cbd25]