I do not think I have seen any LEGITMATE online manga (please tell me if there is). I doubt there are any online manga in ENGLISH if we were to be sensitive to the exact definition of "manga". Hence, my vote was "There's such a thing as online manga??!"
Now if we were to talk about certain manga involving scanlators, I admit that I read them but feel very guilty since I, as a fan, am not supporting the people who made the manga in the appropriate way. I also feel spot on depressed that I also do not have the financial means to support them the appropriate way but believe me, I would pay if I had the money TT3TT
Going a bit off-topic but, I believe some people mistake "Manga" from "Manga-style Comic", if that made sense to anyone >_>
Is that enough for you? There are tons of other places to find online manga, like the scanlaters, such as Aerandria or Odd Squad Scanlations(hehe just came to mind, they scan one of my fave mangas, 1/2 Prince) XDXD
or you can buy a psp, hack it to a certain firmware that still supports "PEPviewer", then just download the batch of images >_> but that would be like i was telling you to support piracy and all that crap so you didn't hear that from me