Yes. Every Urbit runtime environment comes with the ability to generate a "comet-level" identity. These are temporary IDs that you can use to test the operating system. To use a comet, you can run ./urbit -c comet instead of ./urbit -w YOUR-ID -k YOUR-ID-1.key --http-port 8080 --ames-port 34543.
However, the downside of doing this is that comets are often blocked by other users due to their potential for abuse. Further, the Urbit core developers are also considering the possibility of removing this feature in the future.