Hi,

You could do this way:

1. Create a page, leave it's URL to whatever is generated automatically. If you call the page "Cool External Site" the page URL will be ~/cool-external-site.aspx, leave it that way.
2. On the new page, add the IFrame module
3. Within the settings of the IFrame module, set the URL to the external site you want to display.

You can see this working on the demo site (until it is refreshed), http://demo.mojoportal.com/cool-external-page

I don't necessarily suggest you do this unless you own the external site and if you do, your users will have a better experience if you theme the external site to be similar to your mojoPortal site and then you can just provide a simple link.

HTH,
Joe D.

You add the IFrame module like any other module. While on the page, click the "Edit This Page" link in the Admin Toolbar, select IFrame from the Feature dropdown and click create.