Since I had to send my original passport with the renewal?
For most countries, especially since the introduction of biometric passports, the renewal process is really the issuing of a new passport with a different passport number. So, your old passport number is essentially worthless once you apply for a new one, and you only find out your new passport number once you receive your new passport. If you have to apply for a visa, you are out of luck: you should have asked for express passport processing (most countries allow this for a fee), if you havent you will need to wait for your new passport to arrive. Obviously, traveling internationally is out of question unless you can use another piece of ID (e.g. European citizens can use a national ID instead of their passport when traveling in the EU). If you are asked to give your passport for less-official purposes (including a flight, provided you dont need a visa, in which case the above applies), you can still use your old passport number (hopefully you made a copy at some point in time) and then update the information when you receive the new document.