I believe this is one app that is definitely needed for all the non-visual-voicemail users out there. We really need to develop an app which will solve the problem of SMSs being ignored when sent from short numbers or alphanumeric senders like banks, and since it isn't trivial to fix this in the iPhone software (I believe 1.1.1 does NOT fix this issue either), then we need an app to:

a) allow you to directly view the SMS messages stored on your SIM card (ie. the ones from voicemail and banking/online institutions which get blocked by the iPhone's SMS application and never appear, but are stored on the sim)

Once that's done, then the next step is:

b) even better, a new app that can show up a notification when these type of SMSs are received (either instantly, or by polling the SIM every 5 mins or so) - I know if that were developed that I'd be donating and putting it straight on my dock so that I could see when voicemails etc arrived

Absolutely, we definitely need this - I'd donate to anyone willing to begin development in this area!

is it known that these sms messages are actually stored on the sim?

The problem I see writing an app to read the sim directly is that the required /dev/tty.baseband is used by the commcenter, and can't be used simultaneously by other apps.

I had the same Idea.
because I think the SMS is stored. if you send an SMS vie Skype for example and have you phone next to a speaker, you can hear the activity of receiving.

when putting the SMS in an other phone, you see them right away.

I tried to read via terminal - but was not very successfull. First - as eagle mentioned - the baseband is busy. but even after stopping the commcenter and using the minicom, it somehow did not work for me to execute the corresponding AT+ command (unknown)

I've been doing a bit of digging around on this.

Seems like there is only ever 1 sms kept (the last recieved) in the sim at any one time.

AT+CMGL? just returns OK I think it's usually meant to return more info on how many sms are in the sim

AT+CMGR=0 returns a valid PDU for the last received message.

AT+CMGR=1 always seems to return ERROR as does any other index >0

I was able to retrieve a voicemail SMS notification from the SIM which does not appear in the SMS application on the phone... so there is hope for a solution.

I think I might do a little more experimenting with this.

This would be a great app as I don't see Apple fixing this soon.