What to talk about when convo turns staleWatch
If you have been conversing for a good 3 or 4 hours, there is nothing wrong with calling time on the date, or even suggesting you go for a walk, actually I had one date where the walk after what I considered the orginal date, was better. It also usually sparks more conversation, one of you will see something, make a comment, and the conversation will begin again.
If you have been talking for half an hour and you have run out of things to say ...maybe you should consider how dating this person long term will be.
(This could apply to friends or your partner)