techniques to indicate hyperlinks in frame

[Kevin Hunter]

hello everyone,
 
This is not strictly a Frame technical issue, but could turn into one, so I thought I'd try you first.
 
We use frame to produce software user guides which we make available in print or as PDFs. Being a software guide, we have frequent web links for additional info of various kinds. 
 
I'm looking for a simple but effective technique of visually indicating, in the PDF version of the guide, that certain text strings are hyperlinks. 
Ideally, this technique would be invisible in the print version, where the links obviously wouldn't work.
 
I don't want to include full URLs in the text flow because they can be long and ugly, and functionally useless: ie, no one is going to type in a 200 character URL (which may be the actual address address of a page, with all it's parameters, to subscribe to a web event) when the same URL can be gotten to by clicking a link directly from our home page. So in the text, I want to tell them how to find the link, and in the PDF version of the guide, I want part of those instructions to also BE a hyperlink. 
 
I've thought of using a simple icon to include within my text flow, which I'd hyperlink. This icon would be visible in both the printed and PDF versions of the guide, as I'm not sure it'd be worth the hassle to condition it out of the PDF I send to the printers. This isn't necessarily a totally undesirable solution, but I was just wondering if anyone had something more elegant, or knew of a standard for this type of thing.
 
Thanks in advance for any suggestions. 
 
Kevin Hunter
BCD