Meta-tags "Viewport", "MobileOptimized" and "HandheldFriendly" can be used to provide appropriately formatted HTML-content to mobile devices. Are these tags good things? They seem pretty platform specific in many cases, and even when not platform specific (viewport), they seem to require device specific attributes in order to work properly.
Should they be used? Where and when is it appropriate to use them? Are there alternatives (without user-agent recognition)?
Note: I have been using CSS media queries to achieve mobile-support, but this requires some UAR in order to get optimize font size.