Am looking for a robust solution for portable hard drive to tote along with
my laptop.

Looking into the new SSD (Solid State Drive) with a portable, self sufficient
(power via USB), portable USB HDD case.

The SSD I am looking at is the 250 GB model from OCZ.

Does anybody have any experience with this new type of HDD? If they are
so good, why are there not more on the market? OK, with time more will
show up...

It's a new and therefor expensive technology. Flash based storage can only be overwritten a certain number of times. I don't know how this currently compares to the life expectancy of conventional hard disks.

Of course there are also advantages, most notable the shock resistence.

A conventional 2.5" external hard disk with 250 GB goes for around 110 Fr. at Digitec. The SSD you're considering is 1029 Fr. over here.

Here the OCZ Guide to configuring and setting up the SSD drives.

The MTBF is running anywhere between 1.5 and 5 million hours. Enough
time. This is, of course, not the overwriting capabilities that you
mentioned.

In all the material I have read about the SSD drives, nobody has
mentioned anything about limited overwriting, where do you get this
info?

A standard HDD is cheap and easy to get my hands on... But not
robust. I mean, what kind of fall would a HDD need to simulate 1500 Gs
of impact force? Surely I would not subject my HDD, or any of my
equipment, to this kind of punnishment

As for the price... yes, costly! I can buy at purchase-price at some
distributors, including at the link you sent. Looking around at this point,
surely the prices will come down... eventually

Just search the web for "write cycle SSD". It has been discussed in PC magazines, too, a few years ago. Apparently the endurance has much improved.

Regarding the 1500 G, a pen falling from your desk can experience an acceleration of 500 G on impact by stopping "instantly"... Granted it has less mass, so the impact energy is smaller.

unless you need the high read speed and low power consumption don't bother Scott, they are more durable than traditional disks but can still fail. As you know if the data is important you need to avoid a single point of failure.

Oh yes, this is soooo true! Had my fingers burned already. Thus the
massive investment in RAID memory and backup drives.

Thanks peachy, my curiosity is up, my wallet is not open yet... way too
much $ for the capacity.

This from clumpc.com:

[snip]
The second reason SSD wear concerns are overrated is a little more
technical, but a lot more logical. According to StorageSearch.com most SSD
drives available today are rated for 1 - 5 million Write cycles before failure
would normally occur. The fastest SSDs can write at 80 MB/s. While we do
not currently know what the SSD inside the EeePC is rated Write
cycle-wise, we do know that according to wiki.EeeUser.com the EeePC can
only write as fast as 1.1 MB/s to 3 MB/s max. Judging by those numbers it
would take the ASUS EeePC’s SSD 84.5 years of constant writing before
failure. Even wiki.EeeUser.com’s somewhat conservative guess that the
EeePC’s SSD would fail after around 100,000 - 200,000 write cycles still
means about 25 years of normal, 6 hour a day use before failure.
[/snip]

One thing I have learned today... SLC & MLC - SLC have about ten times
the rewrite/overwrite lifetime than MLC.