I notice many of us do not live in the US, and may not have access to a High Quality version of IOMG online.
However, my brother hosts his own site, and he usually uploads HD episodes of Icarly, 1 to 2 days after they have aired in the US. Honestly great quality. IOMG should be uploaded latest Monday (11th of April), but if you're lucky, Sunday ;)
Just visit Imzigamer.com and scroll down the home page to the 'Favourite TV Shows viewed' and then 'ICarly - View Episodes'
Sorry I was unable to post a link.
All Episodes of Icarly, from Season 1 till the latest Season 4 episodes should be there for online viewing, or downloadable.