Drop down lists in Widget ?

I’m using twenty ten theme, and I would like to have a list of my services in a sidebar widget.

I am able to make my list with bullets just fine, but here comes my question.

Is there any way to have a list that when you click the top item, all the sub-items would slide out from beneath that first item.

Good things
– kittens
– puppies
– moms
– ice cream

You would only see “Good things” in the list on the sidebar widget until you clicked on it, or perhaps beside it then all the list of good things beneath it would slide out beneath it so you could see all them.

TIA…..