What do you mean post on other peoples things?

To send a message to another user, you can either press reply next to their status, or in your status, put @ followed by their username on the site.

From what I have read and heard, this is for mobiles, like the Iphone, which I do not have or blackberries and you have to be signed up with Vodaphone.

Is that right?

Nope, you can use it via the web, and any phone network.

You can use it, but you will not receive txt messages or updates, or whatever you want to call them, to your phone... unless you're with Vodaphone.

any mobile phone and or the web. to reply to something been said start your tweet with @ username for example @ officialbb. for all big brother fans to read your tweets put #bb10 any where in your tweet
. to follow people go to there profile and click on follow and then all there updates will show on your page.

To post stuff on other peoples news feed they need to choose to follow you, start spreading your account name round and people start following, the more followers you get the more active twitter gets. Start following people too, then you can start replying to them and then they might start following you.

it can seem a tad boring at first but once you learn a little more it does get good i love it now