After spending many hours using a Pocket PC for navigation and weather,
I feel that PDA solutions can offer tremendous value but are not for
everyone.

If you are tech savvy and do not need the PDA for primary navigation
you can potentially save many thousands of dollars vs. the cost of
panel mount units and proprietary weather data feeds.
Keep in mind that the underlying PDA operating systems are imperfect
and can fail you at inconvenient times. Are you ready and willing to
perform soft resets, define Bluetooth connections, proactively manage
memory (i.e., don't run a bazillion applications at once), move
files, configure Internet properties and acclimate to a screen with
tiny fonts?
If not, go straight for a dedicated aviation handheld or panel unit and
get regional NEXRAD on your cell phone. That will keep you out of the
worst weather. All NEXRAD data is minutes-old information regardless of
how much you spend to get it and is not suitable for picking your way
through storms.

For missions that include hard IFR, I would want an in-panel display
with a satellite NEXRAD receiver and an independent storm scope. The
PDA would then make a good backup.

One benefit of having a PDA is the wide range of aviation specific
software applications. Mix and match to suite your needs without being
locked into the offerings of a single vendor. Much like choosing a
wine, start at the low end and work your way up. When you find one you
like, stop.

If you have a Pocket PC and an in-cockpit Internet connection
(satellite or 'cell' phone), you can get a moving map with NEXRAD
for a monthly cost equivalent to a couple quarts of Aeroshell 15w-50.

I cringe when I read about pilots spending thousands of dollars on PDA
based solutions. Hundreds is about right, not thousands. If that spare
change is burning a hole consider spending it on training or maybe a
2nd AI.

Search google using = Pocket PC Moving Map NEXRAD METAR
for some on-topic links.