Interesting thread... I was curious how it would play out. It sounds as though I might be "odd man out", as my primary hardware is all Apple. I was one of the original authorized "value-added resellers" for NOAA's RNC charts when they first went into the public domain in Nov, 2005. As such, I've experimented with most of the popular charting software on both Mac and Windows OS. There are many good options out there, both laptop-based and standalone GPS. At last count, I had over 40 different ways to get GPS on my boat. That may sound absurd, but it counts each of several Nav Apps on my two primary Macs (each with Mac & Windows installed), an eeePC, 2 Garmin Chartplotters, 1 Garmin NUVI 500, iPhone and iPad. I primarily puchased the 3 Garmins as backups, since I already had every Garmin chart for the world.
Of the lot, I believe the iPad to be the most promising platform, both now and future. (I'm assuming that you were referring to the iPad, when you mentioned iPod, Jim.) The developer of the best Nav app for iPad (iNavX) is also the developer of the two best Nav apps for the Mac (GPSNavX and MacENC). Both of these are exceptional apps, though MacENC is the way to go of the two, as it will load both RNC and ENC charts. Rich Ray, the developer of these apps and a business colleague, firmly believes that the iPad is unquestionably the future in marine navigation... at least as far as non-dedicated devices go. He has, in fact, pretty much put the Mac-based apps on the back burner, in order to concentrate on iNavX development. From my own experience, I would definitely tend to agree.
There are lots of products available, in both hardware and software. And there are pros and cons to each. If you haven't taken a serious look at the iPad for navigation, you owe it to yourself to do so.
Just another man's opinion...
Jack