So I've been working on a few projects in which I've found a number of bugs. It turns out I found 3 in the time span of 20 minutes and I sent them merrily along to the developers ...<p>Is this bad etiquette? Should I be waiting a day / a few hours between submissions?
If you find bugs, then you find bugs. Just make sure that the bug hasn't already been reported, and that it is actually a bug (not just you expecting something to behave differently - the unexpected behaviour may be intentional, or at least documented)<p>Other than that, though; bugs are bugs, and waiting to submit them to spare a developer's feelings doesn't really help anyone.
If the bugs are new it shouldn't matter how quickly they are filed.<p>Do be sure to <i>search</i> existing bugs before adding more however. A unique bug report is helpful but a duplicate can be a nuisance. Sometimes the duplicate will be a closed bug too, e.g, "we found this and decided not to fix it for the following reason:".
I think sending as many as you find when you find them is fine, as long as you present yourself well. I recently wrote (and have given this presentation at a conference) on the topic of communication etiquette in bug reports for open source, believe it or not.<p><a href="http://www.alfajango.com/blog/communicating-with-engineers-and-contributing-to-open-source/" rel="nofollow">http://www.alfajango.com/blog/communicating-with-engineers-a...</a>
If you found them in the first 20 minutes of using the program, there's a good chance they've been already reported. Search the bug database before submitting, if these are indeed new bugs, developers won't mind if you submit a bunch of them in one go.