If one of the folks in Radio Shack or Service Merchandise (but they're out of business now) asked for my phone number I always told them to put in 555-1212. The number for "Information" here in the states.

At the university where I work they use our SS# as id, but upon request, I can think up another number and they'll use it instead. I just have to remember what it is, once I do that. I've considered using an old id number from one of the colleges I attended ages back--chances are no one would figure out where I went to school 25 years ago and that this number was a part of one of those systems. But I still remember those numbers, which is handy.

SRS