I came across some weird behavior in Firefox 12. Consider the following HTML:
<!DOCTYPE html>
<img src="resources/csv.png">
<img src="resources/globe.png">
<img src="resources/clock.png">
<img src="resources/key.png">
<img src="resources/delete.png">
When this is displayed, I noticed there is a small space between the first and second images. If I make a “text selection” around all the images, I see there a hidden little white space between them:

I can't think of any reason for this, but I intend to make all my button links, so I also tried this to see if this has any effect. Here's the new code:
<!DOCTYPE html>
<a><img src="resources/csv.png"></a>
<a><img src="resources/globe.png"></a>
<a><img src="resources/clock.png"></a>
<a><img src="resources/key.png"></a>
<a><img src="resources/delete.png"></a>
Once again, here is the output that has been selected. Note that there is a space after each image:

- ? HTML , , Firefox? - , , CSS? - , IE7, , , , . .
EDIT: . , HTML. , .:)