On every cellphone, PDAs and non PDAs alike, that I've encountered, the IMEI can be easily obtained by dialing *#06#. The only other way to obtain it is by removing the battery, and reading it off the barcode sticker in the battery compartment. When troubleshooting a phone, the SIM number is often just as vital, yet the only way to obtain it is to remove it, which requires powering off the phone, in most cases removing the battery, removing the SIM to read the number off it, the putting it back in, putting the battery back in, and turning the phone back on, which can take 3 minutes or more in high-end smartphones.
So my idea is this: a dialable number like the IMEI retrieval number to quickly and conveniently obtain the SIM number. It may be possible on certain phones to locate the number somewhere in the menus (if there is, the walkthroughs and tutorials don't say how), but I feel that a standardized, quick retrieval protocol would make things much faster and more convenient.-- 21 Quest, Sep 06 2009 I have to admit i scarcely know anything about cellphones, but would this scheme not make the SIM (=password?) available to anyone who has a few seconds access to your phone?-- loonquawl, Sep 07 2009 Regarding those codes, is there a list anywhere of published, standard phone diagnostic codes? Are there any cool ones?-- zen_tom, Sep 07 2009 If there is, I haven't seen it. The coolest, though, would be the one that reregisters the phone with the network, which is freakin' awesome when troubleshooting. I can't remember that one off the top of my head.-- 21 Quest, Sep 07 2009 4 fishbones with no explanation? What gives? The SIM wouldn't be anymore exposed to theft than the IMEI. What's the deal?-- 21 Quest, Sep 07 2009 We have hundreds of field-test displays, for everything from network and bluetooth stats, WiFi and BT MAC addresses, to energy management and signal strength. They're disabled for production builds.-- AbsintheWithoutLeave, Sep 07 2009 Why?-- 21 Quest, Sep 07 2009 Because they're irrelevant to 99.999% of users.-- AbsintheWithoutLeave, Sep 07 2009 random, halfbakery