Check back on this post from time to time. I plan on updating pictures as more parts finish.
I received a sample of filament from Colorfabb.com today. They make a PLA/PHA blend. Major advertised benefits being that it prints similarly to PLA, but has some added toughness from the addition of the PHA. To me, this sounds like a dream. None of the fighting with warpage and build plate adhesion that you get with ABS or nylon without the brittleness of standard PLA. Rumor has it that it also prints a little smoother making the layers a little less visible. It's a little on the pricey side, but is reasonably comparable to other premium PLA.
Our samples are being tested on an Ultimaker, a Makerbot Replicator 2, and a Robo3D. If all goes well through our testing, we will be ordering a bunch of spools to distribute to a handful of lucky US 3D printers at a group buy prices (both 1.75mm and 3.0mm sizes). If all goes well with THAT, then we will be offering this material for resale in the US. If you are a prolific PLA printer and want to try something new, send me a message. My initial perception is that the filament itself is significantly more flexible than straight PLA filament. It also just feels smoother. So, for starters, here's a Stretch Bracelet in Magenta. Ultimaker at 0.1mm layer height.
I tried a little impromptu mechanical testing with the bracelets. My sister-in-law snagged the magenta one, but I printed another in ultramarine blue, then printed another in regular grape colored PLA. I then pulled them until they broke. The standard PLA elongated to about 5". The PLA/PHA got to about 8.5". More important than the total elongation may be the failure mode. The regular PLA shattered into 2 fragments, snapped back, and cut my finger. The PLA/PHA broke at a single point with a lot less force. So, this definitely supports the more ductile type claims. I also broke them into more pieces because I like to break things. Here are the pieces.
Next up I tried out a no coin bottle opener. Rush print on this one at 200 micron in blue grey at high speed so the layers are a little rough. Opened up my bottle with no issue!
No coin bottle opener mk. II (JeppeHeiniMikkelsen) / CC BY-ND 3.0
You tube video of it in action: Another off the ultimaker by one of my favorite creators.
NOW we get to the really good stuff. I also received a sample of their new material XT. This prints at a higher temperature, but is still a biopolymer. Not exactly sure what the blend is, but it smells like sugar when it melts. Another stretchy bracelet
Some tensile dogbones (guess what I'll be doing with these?)
Finally I ran this.
I wasn't paying attention and initially printed it at tiny scale. Here it is in my wedding ring.
I ran it again a little bigger. It's kind of hard to capture the detail in a photograph, but this material is really amazing for 3D printing. The layers blend together incredibly well giving it the appearance of a matted molded part. 
PRUSA RESEARCH ACQUIRES PRINTED SOLID INC. TO EXPAND DIRECT SALES AND SUPPORT INTO THE USA
I tried a little impromptu mechanical testing with the bracelets. My sister-in-law snagged the magenta one, but I printed another in ultramarine blue, then printed another in regular grape colored PLA. I then pulled them until they broke. The standard PLA elongated to about 5". The PLA/PHA got to about 8.5". More important than the total elongation may be the failure mode. The regular PLA shattered into 2 fragments, snapped back, and cut my finger. The PLA/PHA broke at a single point with a lot less force. So, this definitely supports the more ductile type claims. I also broke them into more pieces because I like to break things. Here are the pieces. 
Next up I tried out a no coin bottle opener. Rush print on this one at 200 micron in blue grey at high speed so the layers are a little rough. Opened up my bottle with no issue! No coin bottle opener mk. II (JeppeHeiniMikkelsen) / CC BY-ND 3.0
You tube video of it in action: Another off the ultimaker by one of my favorite creators.
NOW we get to the really good stuff. I also received a sample of their new material XT. This prints at a higher temperature, but is still a biopolymer. Not exactly sure what the blend is, but it smells like sugar when it melts. Another stretchy bracelet 
Some tensile dogbones (guess what I'll be doing with these?) 
Finally I ran this.
I wasn't paying attention and initially printed it at tiny scale. Here it is in my wedding ring. 
I ran it again a little bigger. It's kind of hard to capture the detail in a photograph, but this material is really amazing for 3D printing. The layers blend together incredibly well giving it the appearance of a matted molded part. 