Frames Frames and more iFrames! (January 09 2008)
A benefit of using frames or iframes is it allows you to improve the ease of use for your website, if done right.
Done wrong is when the viewer can obviously see the scroll bar of the iframe. I have yet to see a webpage with two scroll bars (besides an input text box) that looks good.
Before, iframes weren't such a bad thing if they were placed properly and not viewable as iframes. Now, that more and more people are catching onto AJAX (Asynchronous JavaScript and XML), the use of iframes has diminished. With frames, you could run the function or query within the browser and now with AJAX you can do the same thing.