Until now there has been no way to give people comment-only access to a document in Google Docs. That’s a problem because you may want feedback on a document without letting someone actually change it. According to this Google Docs blog post, Google Docs accounts will start gaining the option of sharing a document with people in such a way that all they can do is add a comment. You can even set public documents such that anyone can comment. With this change, Google Docs becomes an even more valuable collaboration tool — there’s almost no reason to mail Word documents around for comment any more. follow link
Copy Before Submitting Web Forms
Filling in Web forms (like the one used to submit this tip) can be a bit of a gamble - you put in your pearls of wisdom, perhaps only to lose them all if the Web page flakes out or the browser crashes. Instead of losing all your text, "save" it by pressing Command-A to select all and then Command-C to copy the selected text to the clipboard. Do this periodically as you type and before you click Submit, and you may "save" yourself from a lot of frustration. It takes just a second to do, and the first time you need to rely on it to paste back in lost text, you'll feel smart.
Google Docs Gains Comment-Only Access Option