*#SIM

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.