One thing I run into a lot in the Desert Southwest is people who want to switch from the tank type water heater to tankless. A lot of people everywhere are making the switch and it's a great idea for energy savings. Really, it just makes sense-- why heat forty to fifty gallons of water around the clock when you can have hot water on demand with no tank and no worries of a hot water heater tank leaking or bursting. (I think we've all had that catastrophe at some time or other.)
I understand that everyone is not in a position to get a tank-less water heater installed with the economy this weak. If you've priced a tank-less water heater, installed, it soars into the thousands. I have five to ten homeowners per day asking about tank-less water heaters. Generally, I have found that the majority are tired of waiting for their hot water to make it to their faucet or shower once they turn it on. Waiting for the hot water to arrive, sometimes for minutes, is frustrating, time-consuming and it hurts watching those dollars flow down the drain!
Luckily there are less expensive solutions for this problem and a tank-less water heater alone will not solve the issue of slow hot water heating in most cases anyways.
The best thing on the market right now for solving this problem is a pump that you mount on your water heater called the Grundfos "Comfort Series". It works by placing a tee like valve underneath the farthest fixture from your water heater and that valve works in conjunction with the pump that you mount on the water heater, itself, to draw the hot water to the valve and push any cold or lukewarm water out of your hot line and into the cold side through the valve.
If you'd like to try this pump, it can be found at Amazon, where there are always good prices, Free Super Saver Shipping, and Front door delivery! You can beat that.