I was introduced to SocialToo by a direct message from a new person I followed today.
We have a couple of projects running at the moment using Twitter for support or for creating networks (smallworlds and PLEs) and having struggled with ways to keep track of new people signing up to the service at the beginning of each project and automated way to do this would be great.
SocialToo allows you automatically send a DM with a message (written by you) to anyone who follows you and can be set to automatically follow them back. This was the first time I had had a DM from someone I had followed and it made me feel all warm and happy and wanted, especially as David followed it up with a DM of his own asking me something simple about my work based on my twitter profile statement. Very smart, great way to build a network.
I could see this working with our students, if they have just signed up to twitter and accepted the default settings, a DM would generate an email to them, pulling them back to twitter and it would be a personal contact.
You can only associate one twitter account with each socialtoo account, so haivng created multiple twitter identities for our different audiences, we would need matching social too accounts. Having said that, it is a one shot deal, set up the account and leave it to work automatically.
You can also set the account to automatically unfollow anyone who unfollows you, though I am not sure we would want this with students on our undergraduate course. SocialToo also has a survey tool which can be used to post surveys to twitter, could be useful for getting quick and dirty feedback on topics, issues etc.