You have two choices:
1. run the print stuff on the client's machine (i.e. an
applet)
2. find the user's printer and queue the job over the network.
1 is easy enough. 2 however is not. You would need all clients to be on the same network as your server. Print jobs generated by the Printing API tend to be very large (everything is an image) so you may well take a big performance hit trying this. Users would have to set the name of their printer in your app (you can't just call the default, because as far as the serverside code is concerned, the default printer is whatever is set up as default on the server). So I wouldn't recomend it.
[ June 04, 2004: Message edited by: Paul Sturrock ]