Specifically, I need the easiest possible way to store Namecoins mined through merged mining, so the eWallet will have to deal well with generated transactions. Do any NMC eWallets actually exist? Do any of the exchanges deal well with generated transactions at receiving addresses?
I would recommend VirCurEx. You can use it as a wallet or trade between different currencies.
I would definitely recommend Vircurex. They support many different currencies, and real easy to set up.
Just checked, and there is a significant lack of wallets just a few months later. The only one that seems active at all is the command-line wallet. The YouTube link below can help you identify the NMC wallet's address from the command prompt in Windows, and the other link is to the page where you can download the NMC wallet's software.
BTC-e.com doesn't have e-wallet capabilities. Their deposit addresses (as David Perry so helpfully pointed out) limits the duration of the deposit addresses, and you have to have a wallet to withdraw to.
I'm just waiting for someone to come out with a good GUI wallet that's easy to use and doesn't require programming knowledge to implement (source code is good, precompiled executables is better, and both is the best).
In just a year, we've gone from over a dozen clients to less than 4 which seem to be currently kept up.
http://www.youtube.com/watch?v=ezo1t90QLFQ - Very simple tutorial--TAKE NOTES!
http://dot-bit.org/ - Links are on the right-hand side of the main page.
As a developer, I find it sad that nobody has created a modular, extensible, multi-currency client.. Free or otherwise. From a technical level it's not much more than a network protocol, handler, peer manager and a handful of block crypto components. Honestly, all of the code we need is already available in multiple forms in just about every mainstream programming language.
These should be swappable/pluggable components by now.
I don't have the luxury of writing e-currency clients for free, otherwise I would take a stab at it or even join a team of people who feel the same way I do, but bills need to get paid. I imagine this is the same reason why no high-quality, polished GUIs exist for the dozen or more e-currencies that now exist. The money to support that kind of development is probably being squandered on 'the Thps race' instead. Heck, you could contract a small development team for as little as 5 BTC a week (at current exchange rates) all you need is a good manager and software engineer on deck. But, nobody has the chops (or the money/freedom) to do it. :(