Embed Excel spreadsheets and charts into your web pages/posts, not as static tables but as "live" data via Excel Web App
"With the Microsoft Excel Web App, you can embed spreadsheets on websites and blogs and make them interactive. Check out the examples on this page to get great ideas for how you can use the Excel Web App
What I thought cool is that the embedded sheet is not just a static table, not just html pasted in, but a "live" view. Whereas you can select cells, use filtering, sorting, etc, etc without any plugins!
And what's also cool is that you can do this inside your firewall too... If you have SharePoint 2010 and installed the Web Apps, you can embedded private, inside the firewall, data into your internal communications/emails, pages, etc. Adds a whole news dimension to sharing spreadsheets...
Not sure if this will work for those picking this up via a feed, but below is a copy of a weight chart I've been maintaining for the last few years, embedding the entire sheet (via an iframe) (and yes I'm working on getting that line to go back down... ;)
And here's just the chart;