There are what's called "hot water recirculators" on the market. There are different variations on the concept. One that's simple to install consists of a small electric pump that would, in your case, install under the kitchen sink. There would be a connection from the hot water line under the sink to the inlet of the pump and the outlet would connect to the cold water line. The pump can be triggered in a number of ways - by a timer, by a manual switch, etc. - which will start the flow of hot water into the cold water line. Sounds odd, doesn't it? But basically it's creating a circulation of pulling in hot water and pushing it out through the cold water line.......thus making hot water more readily available at your sink. You'd have to fire the pump up a minute or two ahead of when you'd really want the water. Arguable downside: You'll have hot water coming out of your cold water faucet for a while after you fire up the pump. Google "hot water recirculator" (without the quotes) for more info.
If you want the hot water instantly at any point in time, then an instant hot water heater would be your best bet. But that's for drawing hot water from a separate dispenser head and might not be what you're looking for. Google "hot water dispenser" (again, without the quotes) for more info.
Hope that helps!
Bill
