2nd one is nice and sharp, background is a bit too bright for my liking on the 1st though.

First one is spot on, maybe brighten it a bit but otherwise a fantastic capture!

If you buy the official Samsung or Pentax remote they won't look the same, but as George says I'd be very suprised if they didn't work on each other.

Depending on how consistent the boats are in where they pass you each time, you could manually focus on a certain corner or section of the circuit, and fire away as a boat passes through. If you can get the panning technique you get great action shots, and it also takes more skill than having a fast shutter speed and simply freezing the frame. Be prepared for a pretty low success rate though, I've used a shutter speed of about 1/250 on remote control cars, but these move through the field of view very rapidly so unless you're up close you could go for 1/125 or whatever works. Concentrate on keeping the crosshairs on the same point on the boat and track it along - it is much easier said than done

There was a thread on this a while ago, and I think if you look at the specification on the Samsung website - it does indeed have a different number of elements to the MkII lens on the Pentax site.

However I haven't actually checked this myself...

I'm increasingly wanting to get a nice prime, and I want to go for the 300mm DA*, potentially for wildlife but also for sailing/car photos.

Anyway, best price in the UK is between 800 and 850 - which stretches my student budget a fair bit

Saw this on ebay and I'm tempted by the fairly large saving...
http://cgi.ebay.co.uk/Pentax-SMC-DA-300mm-f-4-ED-IF-SDM-fr-K10D-K20D-NEW-UV_W0QQ...

They have good enough feedback, I guess it's just a case of trust? As well as hoping it doesn't get stung at customs.

I keep meaning to do a test and actually know the correct figure - this topic might just make me get off my backside and do it. 7x sounds about right though, I use 5 or 6x as a quick check of whether the photo is sharp or not.

Same! I put mine in for the chance to get some C&C as there ain't no chance of winning with what had already been posted!

The Bund, Shanghai.

taken with GX10, 18-55 kit lens. 18mm, ISO200, f6.7, 1/90s

I doubt there's a good way to test which DVD's would last the best over an extended period of time, but the technology has been around for quite a while now. So I would expect any of the big name brands (Sony et al) to be about as good as you can get. As said, put them in a sensible place and there's not much more you can do.