T-Mobile has begun sending letters to remaining Sidekick users in order to notify them that the Danger Services powering Sidekick phones will no longer be operational as of May 31st. T-Mobile first announced the imminent shut down on Tuesday. What can current Sidekick users expect in return for being forced to part with their beloved Danger phones? Half off a select Samsung phone between now and May 31st, or a waived ETF should they choose to take their business elsewhere. Oh, and users will have to sign a new two-year contract should they opt for the discount Samsung phone. Hit the break for the full letter T-Mobile sent affected subscribers.