This was precisely why IR35 was brought in. Employees were leaving on a friday and starting back on the monday as a contractor so as to avoid paying NI etc.
You can work for your former employer as sub-contractor but you must have other clients on your books to avoid IR35. If not then HMRC could consider that you are in fact an employee and potentially fine you.
I currently have an Iphone but am toying with getting a Blackberry as I am getting a bit fed up with Apple and its corporate indifference towards its customer base.....any thoughts / advice on this?