Klaus Komenda has an excellent collection of in-browser tools for web developers on his blog. The obvious ones, Firebug and WebDeveloper, are there, but the article also lists tools for Internet Explorer, Opera, and Safari too.

scienceoss.com has a nice little tutorial today showing how to read in an excel file in Python using the xlrd package. This approach allows you to manipulate excel files on any platform without having to export to a CSV file first. Very handy!