To promote collaborative work, peer assessment and students self-assessing, a really good thing to use is a wiki. You can use tools like wikispaces.com, which is a way to set up free wikis, and you essentially give the students access to that virtual learning environment, both inside and outside of the classroom.
You might have a wiki where you have eight topics, and you have got different students working on different topics- so more than one student may be working on the same page at the same time. And you can do this in real-time, so you can see people typing on the page as you have it open in front of you.
Another effective tool for collaboration in real-time is Google Docs, which is an outstanding teaching and learning tool! Every single student has got their own Google email account, managed from inside the school, so only people within school can email or message you and vice versa. Documents can be created and shared by anyone – with anyone – and these are hosted via cloud-storage, so can be accessed on any internet device, from anywhere. It's also great for writing reports as a teacher because a number of us can collaborate on writing the same report, instantaneously.
When I am trying to add more of a creative element to the classroom, I like students to use the iPad as a creative tool. One fantastic app for this is Explain Everything, it's absolutely brilliant. You can use it as a teacher to create short video files to explain a concept to students, or give instructions for a task and they can replay it as often as they need. It's great for differentiation, in that you can make two or three different clips and can share one with some and another with others. It's also great for students to use to create an Explain Everything from the information they have learnt during class, using the video creation software.