You can buy almost any type of NFC tag, just stay away from miFARE Classic. miFARE Ultralight works very well with the 99xx. NFC Tags, Stickers, Readers and Software | BUYNFCTAGS.COM http://www.amazon.com/Mifare-Ultrali.../dp/B005UIQVB4
You do not need a writer. NFC shortcuts works by associating a particular action or group of actions depending on the proximity of a particular NFC enabled sticker, FOB, card, etc.
You do not need to encode the actual item, as the software takes care of the interaction(s), and you can 'reprogram' (not really*) what actions are taken when you 'badge' your device on a sticker. *Since the software does all the work, you can just change the macro in relation to that tag.
You can set up a tag next to your front door, so that when you come home, you tap your device to the tag and you automatically turn off your radio and turn on your WiFi and connect to your home WiFi network. Anyone who has the same software can interact with that tag the same as you would. I think you need NFCShortcuts+Shortcutme for all that jazz to work.
You can use Smart Tag to create and share NFC tags with web addresses, telephone numbers, open an app or map location, and I think you can also set it to send an automated sms. You can get more info here. About smart tags - BlackBerry Bold 9900/9930 Smartphones - User Guide - BlackBerry Bold Series - 7.0
Looking down on the left, you can also select more information on Smart Tags and actions/uses.
More information can also be found here How to use NFC tags with your BlackBerry Smartphone | CrackBerry.com