In my search for an online recorder, I found http://www.vocaroo.com/ . I am using this to record my student's speech practice so they can listen back to it and score/evaluate their productions. It has been very effective and the quality is really good - much better than those little digital recorders. It also records for as long as you need it to, unlike the sound recorder on my computer! I really like to use it with the Logitech USB Desktop Microphone. Very good speech sound quality to hear those /s/ and /r/ sounds!
Give this sound recorder a try!