How difficult is to create a simple desktop applet with a company logo? Something with simple contact details, but if you click on it, it takes you a website with remote access software?

Utterly simple (for a basic one) -http://www.rw-designer.com/make-shortcut-icon (Windoze)

Sadly the above is not digitally signed, so user will get prompted with a safety warning, unless they uncheck a "warm me every time" checkbox

Alternatively look intohttp://prism.mozilla.com/started/ - I've heard you can "pre-set" and distribute an app using Prism

Finally, an application could be quite easily created (I'd probably use MDM Zinc for cross-platform; .NET for Windows-only) - and you could even make that a flash .exe or an AIR app.