What other elements of assessment might you include?  Consider aligning the assessment to technology or content specific standards.

How can you create a database for these presentations as resources for future use?  Could you create a Delicious tag structure for it?  

Could you provide some links or resources for these tools?  Perhaps a tutorial link to adding these features to iGoogle?

Very well done Objectives page!  You certainly cover the bases with the rationale for this unit.  

Do you think you could provide an article or reading to help support this lesson?  Maybe something discussing the value of food tracking or the risk of "dietary ignorance"?

Consider adding a video or article link for this page.   I think adding some detail to frontload this lesson may help student have some buy-in and sense of direction.  Perhaps a clip (pr trailer) from Fast Food Nation or Supers Size Me?

Is this where the students can communicate about their diet plans?  What does this wiki page specifically accomplish?  Are there any requirements for students to comment on each other's diet plan choices?

Will these tags be carried over to future classes?  How might you make the tagging structure more specific to your courses (so they don't get lost among other general tags)?

Nice use of Google Docs to streamline the process of assessment.

How are these objectives aligned to state and technology standards?  Are those listed anywhere on the site?

I might consider adding some more formatting to this page to make it look a bit more official. The stock photos all have watermark logos on them, so I might find some that look more professional.

Awesome page of resources.  Almost a bit overwhelming.  Definitely useful for students looking for some additional help, and also a great support for constructivist learning.

How?  What is the process for choosing new group members?  Content area perhaps?

Your introduction page is great for getting the learners started.  Very impressive!

Will this include sharing of resources beyond this particular classroom?  What kind of tagging structure will be used?

Is there a specific rubric for this?  What specific information will go on these wikis?  

Consider adding some other criteria such as uses (networking, collaborating, etc.), features, shortcomings, and so on.

Is this the ultimate objective of the lesson?  Will the screencast be geared towards creating these sites?  Why are the Twitter accounts used?  Is this all done remotely?