Some people are really really scared of doing something on their web site that would be considered search spam. So those people ask some interesting questions.

I personally found this question pretty interesting, especially since a Googler responded to it.

A person asked in the Google Webmaster Help forums if he can use the same alt (alternative) text tags to describe the same image but multiple size options. He asked:

Peter Linsley, who was formerly with Ask.com, now helps lead up the Google Image search team, answered the question. He said:

So no, this is not considered spam.

Forum discussion at Google Webmaster Help.