Is it okay to use <input type="tel"/> now?

Solution 1:

Yes, any unsupported type will revert to the 'type=text' format.

I found a good page which lists out all the existing input types. I tried looking at it from different browsers, a bit interesting. Don't know if it will help you or not.

http://miketaylr.com/pres/html5/forms2.html

Solution 2:

Browsers will fall back to type="text" when they encounter unsupported input type. So I think it's OK to use type="tel".

Solution 3:

Short answer: yes. As @el.pescado mentions, browsers fall back to type=text when they don't understand the type. For more info about the other cool features you get from HTML5 forms, check out A Form of Madness, which is the forms chapter in Dive Into HTML5.