These days, a whole lot (if not most) of the agents accepting electronic submissions seem to be using e-readers. This poses a challenge for writers who may not have formatted their manuscript for an e-reader. The good news is, there isn't much of a difference between formatting for an e-reader and the normal formatting guidelines.
In general, using the enter key multiple times rather than a page-break at the end of a chapter or using extra spaces might look fine on the Word Doc version of the MS but will make a mess of the formatting when viewed on an e-reader. And chapter titles with fancy scripts might be impossible to decipher. So, there are some special guidelines to take into consideration when submitting an MS so that both agents using an e-reader or not will be able to view your submission without being distracted by formatting issues.
Here are the resources I refer back to when formatting my manuscript for submission (Of course, these are generalized guidelines and the Agency Website and Agent's blog should always be checked for specific information):
Agent Vickie Motter
Font: Times New Roman, 12 pt
Margins: 1 inch all around
Indent Paragraphs: .5 inch first line only
Scene Breaks: # without an empty line before or after
Also, I do have a Kindle, so I use it to do a last check on my MS to make sure there isn't anything crazy going on with the format.
Is there anything I missed? If you have other formatting resources/information, please share!