http://docs.google.com/viewer (http://docs.google.com/viewer)
o per semplificare:
http://docs.google.com/viewer?url= (http://docs.google.com/viewer?url=)
mettere la url dopo l'uguale :)
esempio
http://docs.google.com/viewer?url=http://onlineconnections.wikispaces.com/file/view/Google+Docs+Tutorial.pdf (http://docs.google.com/viewer?url=http://onlineconnections.wikispaces.com/file/view/Google+Docs+Tutorial.pdf)
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altro servizio Opensource:
http://view.samurajdata.se/ (http://view.samurajdata.se/)