Often when you are writing code or testing an application, it might be helpful to have random phone numbers generated for you.
Here is an excel formula that I use:
try these 2 instead (thanks to John)
=RANDBETWEEN(1000000000,9999999999) [needs analysis toolpack add-in or excel 2007]
Even though it works most of the time as excel rand() formula generates long decimal values between 0 and 1, it often returns fewer than 10 digits. You can add zeros at the left side to compensate that though.
Here is a shared Google docs spreadsheet with 200 random phone numbers generated for you. I am not sure how often Google refreshes the formulas on shared workbooks, so please be patient if you see same numbers generated twice.