Google "Silver Nanoparticles" instead of colloidal silver and you'll find better information and less woo. It has been researched in Asia for over a decade now and the west are yet to catch up.
What is most commonly known as "colloidal silver" is actually ionic silver, or more accurately, silver oxide. Each ion is positively charged and is the smallest particle size. It is typically made by method of electrolysis. It is also the type of silver implicated in the condition Argyria, though not lethal, it does cause a permanent blue/grey color in the skin. To this date, silver nanoparticles have not been found to cause Argyria. They have totally different properties - A silver nanoparticle is a pure silver particle that has thousands of silver ions attached to it's surface. It also has a negative charge and is around 45 times the size of a silver ion. Nanoparticles can come in different shapes - spheres, rods, prisms, cubes... The list of conditions that silver nanoparticles are being tested against is growing: HIV, TB, Cancer, Thrombosis/stroke, Diabetes, hep B, H1N1, MRSA... Google any condition with "silver nanoparticles" and see what comes up.
Fascinating things!