Yes, you can track your bloodsugar readings over time and have a graph generated from them (similar to the weight data).
I believe it is available only to Premium Members, although I'm not positive.
For me, when I am on my Online version account I click on the Reports tab at the top of the screen. Scroll all the way down where it says "Custom Measurements," then click on "Custome Measurements Over Time." You can select "Blood Sugar" in the drop down box, and off you go!