I just got my hands on a supposedly 600-watt rated landscape lighting power supply. It was free (picked it up from the town dump), apparently new in the box, so how could I refuse such  a deal? It's a Malibu 8100-0600-01 "600 Watt Power Pack". It is in an enclosure that is designed for outside mounting, and is hefty enough that it probably has a transformer inside the case. It apparently outputs 12VAC. There is a multi-purpose timer built in to the enclosure.

https://www.amazon.com/Malibu-C-8100-0600-01-Watt-Transformer/dp/B004T3I1VE

I have not yet plugged it in, nor have I yet opened it up to see whether it's just a raw transformer (probably without a center tap). I will figure that out soon enough, but before I do some poking around I was wondering if anyone has ideas for ham radio uses for one of those. It's probably simpler to distribute power to some 'thing' in my yard by using low-voltage AC than it is to go to the expense (and related safety precautions) for distributing standard line voltage. Landscape lighting cable and fixtures are readily available for shallow ground burial of the cable so that, unlike my other around-the-yard ground-level cable exploits, I won't run the risk of slicing it apart when I mow the lawn. Of course at the lower voltage, resistive power losses can be a concern over longer distances - but the cable that they sell for outdoor lighting use is already intended to minimize power losses for typical cable lengths.

One application that comes to mind is running a (not-very) remote UHF transceiver close to the antenna to minimize coax losses - effectively trading some power supply and distribution losses for reduced rf power and signal loss - for example, by building a weatherproofed 'dog-house' enclosure for the electronics at the base of the tower (although, keeping the inside temperature to within an appropriate range may take some planning). I suppose that I could rectify the AC at the 'load' end, and use a DC-to-DC boost circuit to get 13.8 VDC for powering a mobile rig, or maybe instead use a transformer to boost the AC back up to 115 volts, and then use a standard power supply circuit to convert that down to 13.8 VDC - again, not the most efficient scheme, but I like the simplicity, and, did I mention that it was 'free'? (Yes, I can't count how much money and effort I've squandered in the past as a result of capitalizing on 'free' stuff that I got my hands on.).

Anyone do something like this? Am I crazy to even think of doing this?

You could try it, but it sounds like a lot of hassle.  Beware of dirty power out put, lights don't care about dirty noisey wave forms.

If it is just a step-down transformer in the box, then almost anything that I do with that AC in the DC realm (rectify, filter, regulate, boost) ought to fix possible 'dirty power' issues - of course if something else is in the box, then I guess that all bets are off...

I'm only guessing that it's supplying 12VAC at 60Hz, however...

You can build a power supply with it but it will require at least a rectifier and a bank of capacitors. I would add some kind of a voltage regulator, but it may require a slightly higher voltage source than 12VAC. The transformer may have a few additional taps in it but you'll have to open the enclosure to find out and to measure the voltages (if taps are available)
Honestly, I don't see a practical application for ham radio. You can get a nice used 30A, linear regulated 13.8 VDC power supply for about $100 or less.

If you live in a cold climate, 12VAC might be useful in some sort of antenna de-icing scheme.

Back in the days when folks routinely home-brewed 13.5 VDC linear supplies, 18 VAC was a good starting point.

If you're feeling ambitious and have a cheap source for magnet wire, rewinding the transformer's secondary is an option.

Hmm 600 Watts says 50A at 12V, it ought to have some use.

The problem is that it's a "raw" 12 volts AC, not 12VDC that most radios require (to be exact: 13.8 VDC, filtered and stabilized)

Oh yeah, I understand that, we'd need to know the level of the output voltage to be sure. I've seen switching modules back in the 90's that could bring the output voltage up, if there are truly 50 amps available there are lots of possibilities.