Right then, since some people still use vocaroo, here's a quick guide on how to setup audacity and do other stuff to export it then into flac or wav.
You can find audacity here:
http://audacity.sourceforge.net/Download it, install it.
The most important thing for what you need to do is on the top bar, more exactly here
That's the record button. You can press it to start recording. After recording, you'll have in the timeline something like this:
If you don't like the recording, you can always clic the X button on the top left of the timeline in order to remove that and then to click again the record button.
Most microphones have a background noise, and it can be really annoying. So then, to remove that and have a perfect sound, record also for a bit some silence. Then, select the silence part by dragging your cursor on the timeline from the beginning of the silence part to the ending of the silence part. You should have something like this:
Now, go on the top on effects, then go to Noise Removal. Click the button "Get Noise Profile" and the window closes. Now select all the recording by doing CTRL + A and go again to Noise Removal, and then click "OK". You'll now notice that your recording has a bit changed. Try to play it and see the effect!
Now you can remove some parts by selecting them and click Canc, but hey, audacity offers bilions of tools that you can search how to use them on the web or youtube, and I'm not going to cover them here so let's get to the salient point: exporting. Go on File, and then Export in order to export all what you recorder, or select a part and then go to Export selection to export only that! Now, select a path where to put your file. In the file format, you can choose between a variety of files, that includes also FLAC, WAV and MP3. Choose what you want.
Now, you're ready to upload your file to whatever host you want and to post your vocal audition here.