I've tried all kinds of funky methods to make my text fields have a 'bigger' text area (i.e. vertical AND horizontal) on the Web. Generally it means making a Rich Text field and writing some funky code to get that information shoved into a text field (which usually means losing some hard returns, etc...). Well, I accidently found something buried in Notes that made this process VERY simple.
There really is no 'code' for this solution. All you have to do is simply mark the text field as to 'Allow Multi-Values' AND in the 'Options' tab of the field, under the 'seperate values when user enters' section, simply select 'New Line' as one of the options.
Now watch what happens to your text field on the Web browser!