I agree with Mole. There are many names out there entered into the popular lexicon that use "e" followed by a common dictionary term that work. You can never guess though what may end up working.
If someone were to ask me today if "eDiets.com" would be a name a company would WANT to use to start an online dieting service, I'd laugh long and hard, barely able to rise off the ground. With tears in my eyes, I'd mutter... do you KNOW what that SOUNDS like??? Who in their right mind would go to Eey-Di-Uts for advice? :laugh:
But... there you go. "I" on the other hand have been popularized VERY much by Apple. In fact, they clearly have more "I" products on the way past their current machine and software list of: IMac, Ipod, Iphoto, IDVD, Imovie, etc.
In fact... the BIGGEST point one might warn you about is that Apple is INDEED *very* protective of its trademarks, and you may however unintentionally have overlooked the product I left out of the above list....
Apple's Ibook. Fortunately, at first glance, you appear to have a precedent in iBook.com that links to Apple's product at the bottom of its page. Unfortunately (for your domain), one of the reasons they probably HAVE that staying power is the fact that THEY *also* have a trademark on the term (October 8, 1996), and theirs in fact preceeds Apple's own trademark (November 6,1998) by a good two years.
To date, I do NOT believe there has been any successful *registered* trademark for the name "eBook" by itself. That distinction is NOT enjoyed by the term "iBook".
As such...
Appraisal: $0 (You will be stopped from using this particular Domain)
Regarding other names with "I" or even "E" in front... I think if they have NOT been trademarked, they may or may not work... it all depends on each name individually. More often than not, I would say NO. Registrar domain name spinning algorhythms seem to like it though (among other prefixes)!
Our merchant account provider is e-onlinedata Corp. Over time the name has grown on me, so again, you never know.
Best,
W|Z