I did a search and it seems some of them support SMS but I'm wondering if that's just a side feature. Basically I only have a 5 megabyte data cap on my plan and if I used the MSN instant messengers for a week, I use those 5 megabytes and have no more left for the rest of the month. Since that route is too expensive, is there an instant messenger application that sends its messages so they are charged as SMS? Like can I chat with my friend on MSN from my Blackberry and have each message charged to my SMS account which is unlimited?

Wirelessly posted (Breaking Ball: BlackBerry8300/4.2.2 Profile/MIDP-2.0 Configuration/CLDC-1.1 VendorID/102)

I think Oz uses SMS rather than data.
Never used it, and I've heard it's not that great.

There might be some information in the Instant Message FAQ at the FAQ site, lots of info there, and a list of most of the major IM applications.

good luck.

I guess the second point on the FAQ pretty much answers that. So I can't get it as long as I'm with that provider (Telus) because they don't offer an unlimited data plan for any PDA device.

Disadvantages of Using IM Instead Of SMS:

* Cost of software such as annual subscription fee, although this may be still be cheaper than the cost of an "Unlimited" SMS add-on.
* Not good if you do not have an unlimited data plan;
* Overkill, if you only do very infrequent SMS or IM;
* Other people need to run IM software too, or log onto an IM system over SMS. (People can log onto AIM using SMS, so you that SMS users can send messages to your IM client that way!)