You can get a prepaid Sidekick kit for $50.00. You simply request it instead of the $100.00 kit. The 100.00 kit just gives you data right off the bat. If you get the $50.00 kit all you have to do is call t-mobile customer service and request the data to be turned on. It's that simple and does not violate any terms of service. The $100.00 kit is simply a way for T-Mobile to rip off unsuspecting customers.
Nevertheless, Sofi, the Cingular (HTC) 8125 and the PPC 6700 (available on Verizon and Sprint) are the best PDA's in US market. The PPC 6700 is faster and the 8125 is more appealing to the eyes and is smaller. I suggest testing both out.