I would like to link directly to the SmugMug Contact Form using a custom URL in a Text Box. Is there a direct link to the contact form that I an use other than using a Menu content block?
Not that I know of.
There is not a direct link to the contact form. Another option besides the menu content block is the button content block.
You could also add a Wufoo form to your site:
Just add it to a page and then you will be able to share a link to that page using a link.