What i did was install google adb driver package revision 4 from the sdk manager list then downloaded the SuperOneClick v2.3.2 from here.
Multiupload.com - upload your files to multiple file hosting sites! (click the top one).
When i downloaded the SDK manager the top sections under Tools and Android (the top 10 checkboxes) were all checked so i just clicked install and the usb package 4 is already checked too.
I use jzip its free just google that.
Unzip SuperOneClick to wherever you want it plug your device into your pc using the usb cable,(on your device) select settings>applications>development and check the box next to USB Debugging.
Skip the prompt on the device asking for pc companion open SuperOneClick and click Root at the top, sit back and enjoy, worked for me when nothing else would
P.s Im not a developer or Android wiz kid of any shape or form im mearly telling you what i did to get root on my xperia play, it is pretty straight forward the only confusing part is knowing what parts of the sdk to install but i just made sure i had the google ADB driver package and the rest was done for me by the software.