I have a third viewpoint for consideration: I read somewhere that we use entirely too many said's, etc. in dialog in general. Okay, it slashes your word count a little, but consider that your reader is smarter than you think (s)he is. If you have a string of dialog involving just two characters, try establishing which is which, then leave the said's out altogether. Just write the dialog. The reader can usually keep track of who's talking, and, to Sesheta's point, the said's and the like can distract the reader. You want him/her to see your dialog.

If you have more than two characters talking, you may need to clarify more often - but still not as often as novice writers tend to think.