Will a iPhone 4 Sim Card (Telus) work in a Sidekick?

I need to know asap.

Hi yes iphone 4 sim card will work in sidekick mobile only if it is unlocked one .Else if your sidekick mobile is locked to some other network then until you unlock it you can't use it with old telus sim ..You can easily unlock your phone using sites like OnlineGsmUnlock.com here they are rendering unlock code for all mobile models at reliable cost ..After unlocking your phone you can freely use it with any GSM sim...