If there is a lot of custom HTML embedded in the pages (placeholders, tracker, <head>) it would be useful to have a global search and replace function.

At present if I need to change some HTML that exists in many different locations on a site I need to go to each placeholder and manually look for the HTML and again change by hand.

A function to do this for me either across all pages or just the current page would save me a huge amount of time.

I would envision it as being no different to a standard Search and Replace function found in any text editor.