Not sure why this one is elluding me, but , I have a graphics display with
an led backlight drawing about 450ma @ 5v. While a large 7805 is rated for
an amp it's getting pretty hot even with a nice sized heat sink.

Any thoughts on another way to drive this backlight? I was thinking of
running it at 12v (it's going in a radio) and a dropping resistor. What
say?
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If your supply voltage is 12 V and need 5 V @ 450 mA , you have to get rid
of 7 V @ 450 mA or 3.15 Watts
in whatever way you do that . Suggest you stick with the 7805 , and
increase the regulator's heat sink if that makes you feel happier .
You can also spread the heat by adding a resistor 'upstream' of the voltage
regulator.
Say you drop 4.5 V across the resistor which @ 450 mA would have to be 10
Ohms ,2 W (take a 3 or 4 W resistor)
Locate the resistor off any PCB (preferably using ceramic ferrules) in a
relatively open area ,not too close to other components
The voltage regulator would then only have to dissipate 1.15 Watt .

With a switch mode regulator you might introduce RF problems.

Frank GM0CSZ / KN6WH