We do single to 3 phase conversion with drives on a regular basis. The utilities want to charge an arm and a leg to run 3 phase power to the rural locations, so the small to medium farms, sawmills, etc. have to decide how to run their equipment. Irrigation for example is a big deal here in the flat-lands... We've done up to 300hp with single phase feed!
One solution, especially cost-efficient when you have multiple loads, is to use a big DC power supply for a DC bus, then feed the individual VFD's from there.
On smaller, single motor applications, de-rating a drive is more convenient and cost effective. As jref stated, the drives run hot, depending on how hard you push them. So, investing in a much larger drive will help it's life expectancy. Regardless, the de-rate will seem excessive, until you consider the ripple current going on in the capacitors. Don't think you can just add a few capacitors, either, the rectifiers likely will not handle it.
For example, I just did a quick look-up on Control Techniques. For a 25a (3ph) load, you would need a 61a drive. The next frame size would be much better, and give you a little overload capability... A 132a frame size 8 would allow 38a.
As you can see from the shocked responses from the rest of the world, we, in the US, are way behind. IMO, our residential power supply should be 208Y120. This would give use 3 phase to efficiently run our appliances, and single phase for our lights and convenience items.
You can use a rotary phase converter. There are millions in operation. Be prepared, however for the poor efficiency, power surges, noise, and much larger incoming supply required to start the converter. The LRA of a 5hp converter is likely 300-500a.
Static converters are used routinely for light duty loads, like Mills, Fans, etc. They work by using the motor as it's own converter, thus de-rating the motor itself. So, for example if the lift you are working on is rated for 5 tons, don't plan on more than 2-3 tons of real work.