30 Boxes is an online calendar that works great for students due to its simplicity and sharing options. It features RSS subscription to automatically populate the calendar with feed items. Users can even access their calendars on the go.

Gliffy allows students to draw and share diagrams online. You get all of your basic functionality that you would in an offline diagram application but with a few extra bonuses like working online collaboratively and dynamic publishing of diagrams. Create flow charts, floor plans, technical diagrams, and more.

Google Voice is another Google product currently in preview. Google Voice might just revolutionize phone and voice mail. With google voice, you get a phone number that you could essentially use as your only phone number in the (near) future. Essentially, you can forward calls from the google voice number to any number you like and even change what number it is forwarded to based on the time. In other words, you can forward calls during the day to your work phone, in the afternoon to your cell phone, and in the evening to your home phone. You can even have the phone ring on all these numbers at all times if you like. Furthermore, you can set different numbers to ring to a different phone (i.e. friends always go to cell phone, work contacts always go to the work phone, etc.). As if that weren't enough...you can even set custom outgoing messages based on who (or what group) is calling. And there's more!!! Voicemails that come in are transcribed as text and can be delivered via email or sms.

Google Wave (currently in preview) is a new online collaboration tool created by Google. It provides the opportunity for asynchronous and synchronous communication among users. Waves allow participants to share resources, images, videos, documents, etc in order to discuss, collaborate, etc. It's a wonderful tool and my guess is that it will only become more powerful when it is open to all and a little more polished. Even in it's current state, it's quite robiust.

Diigo is the next generation of social bookmarking. In addition to simply bookmarking the page, you can include a snapshot (screenshot to include in the bookmark view),. You can also highlight information on the web page for inclusion in the bookmark (and also to be noted when someone visits the site from your diigo page. Another neat feature is that you can add sticky notes to the page. Again, these will be viewable by people visiting the page from your bookmark page. There are other features. I suggest visiting the page and taking the 'video tour' as you will love what diigo has to offer!