Most of mine appear as a Yahoo host/domain that looks like it is caching mobile.. But I see no purpose behind that caching.. It still merely introduces a second connection slow-down behind any mobile using the caching. My site -> Yahoo -> Mobile.
Unless there is a ton of mobiles all using that same cache to service that exact page before the page expires in the caching system, the cache serves no real purpose. An individual user gets no benefit unless either many others have visited that page shortly before, or that same user is reloading that same page over and over. In the latter case, that is even only under the assumption that Yahoo can load up my content faster than I can.
And honestly, I don't quite believe in it.. Again, because it is a proxy hiding the real user.