Webserver question

Here's a question for any of you webserver gurus out there. I was taking a peek at my log files and noticed that several of these errors suddenly appeared from a wide range of ip addresses for about 30 minutes this morning. Not quite sure what they were looking for and is it a potential secuirty problem. The exact message is

File does not exist: /var/www/html/</a></td></tr><tr><td class=
Originally posted by kosmo vinyl:

File does not exist: /var/www/html/&lt;/a&gt;&lt;/td&gt;&lt;/tr&gt;&lt;tr&gt;&lt;td class=
Downloading too much porn again, eh? <img src="http://pages.prodigy.net/rogerlori1/emoticons/drool02.gif" alt=" - " />
is all that was in the log? seems pretty harmless unless it is a known exploit, but it looks like they may be scanning your server for an exploit, doesnt mean they found it though