well, dang - it seems like either no one knows or no one cares to speak up. well, after a lotta chasing around from documents i can't understand to documents i don't want to understand, i finally found that it's just a wap push (which i'll have to do some reading up on now...)
answer below, thanks to bango.net
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WAP Push messages are specially formatted SMS messages that display an alert message to the user, and gives the user the option of connecting directly to a particular URL via the mobile phone�s WAP browser.
The Bango service sends a WAP push message in response to a TXT Trigger request from a user. The format of the URL to access the content is the telephone number followed by bango.net e.g.
http://447711223344.bango.net Please be advised that there are variations on the name of a WAP push depending on the make of phone that you are using.
Here are the most common ones:
Nokia - "Service Message"
Sharp - "WAP Alert"
Samsung - "Push Message"
Motorola - "Browser Message"
Sony Ericsson - "[name of site/page]WAP"
Sagem - "WAP Push"
Panasonic - "WAP Message"