printing things in Tokyo

Does anyone know of any public place to print documments in Tokyo?
I understand convenience stores can do this somehow? Any idea how?
I've a few shortish PDFs that I need to print but no printer - my friends don't have one either

You can do this at any of the major convenience store chains. Just put your files in a USB flash memory or an SD card and follow the instructions next to the photocopier machine. Usually costs 10 yen a sheet.

Sorry for hijacking this thread, but is there a way to print word documents as well at the combini? I never could figure it out.

I don't think they can print word documents. I looked at several combinis, and they are only compatible with pdf and jpeg files. I would suggest downloading a print to pdf application, which is normally free. That will allow you to convert any type of document to pdf.

You can print PDF documents via USB memory at major convenience stores such as 7-11 for 10 YEN per print.
If the store is not at busy time, ask one of store staff that you want to print from USB memory. If you meet a kind staff I'm sure he/she will happy to assist you.

If you are in Shinjuku then visit kinko's printing service. The staff assisted service will cost more(15.75 YEN per print) but the store assistants are happy to help you. The store opens for 24 hrs/365 days located on Omekaido-avenue near Shinjuku Police Department(right opposite Mcdonald's).
http://www.kinkos.co.jp/store/t008.html