The USB system is designed to have 1Master and upto 127 slaves in one bus.. What you are talking about is connecting 2 masters to each other in the same bus. This is not possible without 2 things. Hardware or Software access.
1) hardware access (would require you to modify your PS3 and add a slave USB connection. And add support in PS3 os for slave usb to work.
2) OS access and modification of PS3 USBHOST/USBHOSTFS and a couple of more driver modification to work as slave instead of master ..
So no.. it wont work the way you are asking. The best easiest and most noob friendly way is to use an external hdd for transfering stuff.