Assuming I understood that question right....You should be able to record directly into audacity, rather than opening a file saved from vocaroo. 

If I recall correctly, you'll probably have to download a thingy in order to export your file from audacity as an mp3. But it gives you prompts and directions. Once you download the thingy, it's a piece of cake. 

From there, you can upload the file to vocaroo.

EDIT: CapnCrunch beat me to it. XD