You can use the cuelist and scene directory windows to run playbacks without attaching them to masters. If you turn off the guard button in the directory, tapping on a directory item is equivalent to pressing go for that playback.
If you want to be able to tap an item once to turn a playback on and again to release it, create single cue cuelists and set the Action at end of list option to Add release end cue. This will put a second virtual cue in the cuelist that will release the list with the second press.
hi Magnus. Another good tip Tom probably forgot to mention is that if you've got loads of virtual cuelists running you can release them by holding down the [List] button and [Release] straight after. your cuelists attached to phisycal masters will still be running. Marco:hogsign: