collaboration - What tools are available for collaborating with a small number of people? -

I am collaborating with a project and currently using Skype for collaboration. I like this because we can say to call to say which is hard to type. We can share our screen so that we can help in writing code. And we can use text chat to copy-paste codes between each other. We also use subversion for version control.

I just want to know what other people were used to cooperate with others, so I can look to use them there.

Thank you!

Anyway, Google Docs also help a lot here! And come at a great price! Their tools comparable to Word, Excel are all free and read for cooperation.