Chris McCormick has done a wonderfull android app, it enable you to run your pd patches on your android smartphone and play with them anywhere, provided that you keep it vanilla.
1- Go there : http://droidparty.net/
and download the apk on your PC
2- Download the attached zip, (it's a tested and working patch.) unzip it on you computer.
3- Search File Expert on the android market and install it (https://market.android.com/details?idxcxin.filexpert)
4- Once file expert is installed, fire it up, and click on Share (in the bottom line) -> choose "enable web sharing" (this will share your sdcard localy). A message appears and gives you info such as an adress, a username and a password (remember it, or keep it displayed onto your phone)
5- On your pc, launch your preferred browser enter the adress, it will prompt you for usename and password.
6- Double click on the big icon, and you have access to your SDcard.
7- Create a folder of you choice (right click -> New Dir), enter it and upload the apk (right click ->upload). Once the upload finished, just click the uploaded file it will install on its own.
8- Go back to the root folder of the SDcard, create a new folder of you choice to put your patches (say "Pure-Data"), enter it. Create a new folder called XY-Pad, and upload all the files from the zip in this folder. "droidparty_main.pd" is the main patch you can have a look at it on your PC first.
9- Close File Expert on your phone by pressing back several times, and launch PdDroidParty it will find your patches on its own.
10- Have Fun !
note : I choose to use an app to share you sd card wia wifi (because it's faster than pluging and mounting your phone each time you want to test something), but you can of course use USB cable to do all the transfers beetween phone and computer. But you'll need a file browser anyway to install the transfered apk
edit : you need to authorize non-market apps to be installed. Just go in Parameters -> Application and check the first box (something like "authorize non-market application")