One HUGE question that a lot of new BlackBerry users and soon to be BlackBerry users ask in the forums is "Can my BlackBerry function without a BlackBerry data plan". Now the most common answer one would come up with is a resounding No! No, it will not function without a BlackBerry data plan. Now, this is where things tend to get a little tricky, due to the fact the answer is not as straight forward as that. While it is indeed true for the most part your BlackBerry will not have many BlackBerry specific features to it, such as BlackBerry messenger, Push Email, RIM/carrier backed IM clients. .etc. etc., you can successfully install some applications such as Opera Mini, Gmail mobile and many others with just a regular "internet" data plan ie: MediaNet on AT&T or Mobile Internet on Rogers or any pay-as-you-go service. Albeit, it's not always easy and not always recommended by your carrier.
This is where Tiggit comes in. Tiggit was designed to utilize your carriers TCP/IP settings to allow access to major email service providers such as AOL, Google Mail, Mac and Yahoo! mail, from personal and corporate BlackBerry smartphones. With support for all devices including the Storm, it's not going to be push email to your device as you have to utilize a specific send/recieve button to bring in email (like WinMob) but it supports WiFi and cellular network connections as well as supporting storage to SD cards of emails and has built in HTML support for viewing your messages the way they were meant to be seen. With the economy being the way it is right now, I could see some users utilizing this option as a cost saving measure, but bare in mind your carrier may not like you doing this as most do *require* you to have a BlackBerry data plan. Tiggit comes at a cost as well. With a 7 day free trial to check out the services it's worth looking into if saving some money in the long run is what you need to be doing, but after the trial is expired the purchase cost is $30.