The way it works is like this, you call the (330) 405-8620 number and give them the model number of your remote (they will assume you have a "One For All" remote, so be sure to tell them first if you have a "Radio Shack" remote), then they ask you what equipment you have and if the codes need to be added to your remote, they will prepare a WAV file for you.
They will then email you a link to the WAV file, but the link is custom for you, it isn't a general link that anyone can use.
Some of the UEI web sites have vanished (like kameleon.com and mykameleon.com), but the download site (ie, ezremote.com) is still there if you can find the right URL for your remote. To download WAV files you will first need to register, then they'll send you a serial number via email that you can use to log on.
Here's some of the remote specific URLs that I was able to find:
URC-8206:
[Link: ezremote.com]URC-8305:
[Link: ezremote.com]URC-8308:
[Link: ezremote.com]URC-7550/7560/7562:
[Link: ezremote.com]Mosaic - Europe:
[Link: ezremote.com]Mosaic - Europe:
[Link: ezremote.com]