Doyer, I have one just like what you posted that I use for my TomTom GPS on my motorcycle. My EVO fits in it but I find that even after a short ride, the EVO heats up quite a bit. It may be that the total enclosure doesn't alow air to circulate or maybe it's because I live in Florida. I didn't feel it was worth the risk to fry my phone.
I found this on eBay ( NEW BIKE BICYCLE MOUNT HOLDER FOR HTC EVO 4G BLACK - eBay (item 150475898006 end time Oct-03-10 01:51:20 PDT)
It's inexpensive, mounted right onto my handlebars (1") and I just got back from a 500 mile weekend ride and it is rock solid. I am very pleased with it.