I've been using these "rum runner" containers for a long time. They're marketed toward the cruise boat crowd for sneaking liquor onboard. I've used them for all sorts of things and they've never failed. I think the plastic is more durable than the Platy's and they're pretty puncture proof.
The plastic's a little stiffer than the Platy's, so they stand up better (they have a pleated bottom). I prefer the spout to be at a corner — easier to pour without spilling. The smaller ones are good for taking wine, liquor.
MOST importantly, they weigh 0.8oz each. I think Platy's are in the 1.2-1.5oz range?
They're also cheap, less than $5 for a 32oz flask, shipping is quick and customer service is great.
http://www.rumrunnerflasks.com/32oztravelerand8482.aspx
Btw, the refillable travel-sized containers on their website (at the 'Easy Travelers' link) aren't bad for packing toiletries and such.