Apple's Airprint currently works on select Canon, Epson, HP, and Lexmark printers.
There's currently a program that can let you print via Airprint to other printers attached to a PC or Mac:
WebOS was supposed to get an ePrint app for printing to HP printers, but it hasn't been released yet.
Google's Cloud Print may be one solution. You should be able to enable any printer for Could Print:
You can run it in Android:
For the HP tablet, the mobile version of Google Docs can print to a Cloud Print enabled printer:
So the process would be: copy the text from the webpage, paste it into a Google Doc, then print the Google Doc.