Hi Carl,
Here's my idea (it needs some HTML styling).
Create a UI Macro (System UI> Macro). Mine is called "website". The name matters because it is used as a formatter which you can add to the form.
My simple UI macro looks like this:
<?xml version="1.0" encoding="utf-8" ?>
<j:jelly trim="false" xmlns:j="jelly:core" xmlns:g="glide" xmlns:j2="null" xmlns:g2="null">
<g:evaluate jelly="true">
var gr = new GlideRecord(jelly.jvar_ref_table);
if (gr.get(jelly.sys_id)) {
gs.log('url=' + gr.u_url);
}
</g:evaluate>
Website: <a target="_blank" href='${gr.u_url}'>LINK</a>
</j:jelly>
Next, create a formatter (System UI> Formatter)
Make sure the Formatter field is the name of your macro defined above.
Finally, place the field on the form using the usual methods (Configure> Form Layout or Configure> Form Design). You will find your formatter listed with the other formatters (like Activities (filtered)).
Granted, mine's not the prettiest thing, with a little HTML style and table for alignment, it can be better. The top URL is the original field value. The bottom "Website" has a clickable link that opens in a new window.
http://wiki.servicenow.com/index.php?title=UI_Macros
Creating a Formatter - ServiceNow Wiki
