Disallow download of a Google Drive file

There is no "fullproof" way to do this. The best that you can do is deter a novice.

Access your file's directory in a browser. Check the box next to your file, click More and choose "Prevent viewers from downloading":

Where to store files?

Until this April, the answer was Dropbox, which provided 2GB of free storage, ways to share folders, and a good automatic sync between your various devices. If you want a short intro to Dropbox, you can find it here.

Google Drive, which came out this past April, can serve the same function as Dropbox in terms of online storage.

Should you switch? If you are using Google software for other things, e.g. Gmail,  it is easiest to use Google Drive for storage. If you are not using Google for other stuff, staying with Dropbox or switching to Google Drive may be a tossup, depending on your needs. If you want to read more on the trade-offs between these two options, Lifehacker has a good article. If you want to read more on many more online storage options, Verge has a good article.

Some lesser-known Google tools

Google Correlate  -- "finds search patterns which correspond with real-world trends."  -- correlations of search terms of Google search users.

Public Data Explorer  -- a searchable repository of public data, together with visualization tools (Google's post on this, Slate article on this). Starting in 2011, you can also upload and visualize your own datasets.

Fusion Tables -- awesome visualization tool that Google uses with Public Data, and that you can use in Google Spreadsheets.

Collaborate via blog? wiki? forum? real-time? - Part 2

This is Part 2 of my October post on collaboration. In this part I discuss the tools available for different collaboration modes and their pluses and minuses. 

Collaborate via blog? wiki? forum? real-time? - Part 1

There are a number of online ways to collaborate and it can be confusing to figure out how they differ. This is a quick summary on the subject. Examples of each of these will appear on the Ed+Tech page shortly.