For those of you who have done projects on the larger side, what do you suggest for connecting multiple strips together. Do you just solder directly, or do you use a JST SM or similar connector? I am leaning towards using the JST SM connector both for a cleaner finished product, and to make any maintenance easier, but I’m interested to hear what others are doing.
Also, how do you handle power distribution - specifically re-injecting power periodically along the strips?
+1 what Jon said … except I get them from my vendors in China, in colors. Similar to what SFE used to sell: https://www.sparkfun.com/products/retired/11182
As for re-injecting power, just add another wire in at the plug. There’s a discussion somewhere that I saw that talks about the proper way to do that … which I never followed. Technically you should not create a “loop”. You should completely cut the VCC line, terminate it on the previous string, then inject power on the next string.
Yep - I had found those on AliExpress and thought they looked good. Thanks for the confirmation. I would definitely prefer the color ones to all black. It should make a wiring “accident” less likely. 
Also, FYI Ashley, unless I am misunderstanding what you are saying, there is no electrical problem with creating a loop. And in fact, according to this post from Mark (and my own testing), feeding power on both ends of a long strip actually produces better, more consistent results.
https://plus.google.com/112916219338292742137/posts/8677tvxjycw
The reason whoever wrote the article said not to, is for interference. A loop will do that whereas the other method doesn’t. However, as I pointed out, I never followed that advice, I just inject wherever I need to just by connecting another wire and not bother with cutting and separating the sections. Also, with a loop you can do it further apart on the string.
Ah - I didn’t think about interference. That makes sense. Since I’ve had good luck just injecting though, I’ll probably go that way. In doing more research this morning, I found some good 2-pin JST connectors that look like they would be great for power so I’m going to buy some of those as well. AliExpress is a useful, but dangerous (as far as my wallet is concerned) place! 
The same goes for alibaba which is the bulk purchases side of aliexpress. I occasionally get a one-shot item from the express site, but all of my bulk purchases go through the other. We need an AAA Community, AliExpress and Alibaba Anonymous. I nominate @Mark_Kriegsman and @Daniel_Garcia as moderators. 
I really like these screw together connectors…
You can combine these 2-conductor ones: http://www.adafruit.com/products/743
With these power T’s: http://shopping.netsuite.com/s.nl/c.ACCT88394/it.A/id.993/.f?sc=2&category=2895
And it creates a really solid, sealed connection for everything. A lot of my stuff ends up rolling around in the desert dust for a few weeks every year, so pretty critical to be sealed and solid.
My current project uses the P9813 “Total Control Lighting” pixels from Cool Neon, so I’m familiar with those 4-pin connectors. They are indeed very nice, but quite a bit more expensive than the JST SM connectors. If anyone wants to buy them though, they are actually a bit less expensive from Cool Neon than from Adafruit.
Yeah, I’m in the same boat. Cool Neon does not yet have the screw on barrel connectors though…
Yeah - those power connectors are pretty cool. I have decided to buy some of these for connecting the LED strings.
http://www.aliexpress.com/item/4pin-JST-Connector-Water-p-Male-female-Cable-Wire-lines-for-3528-5050-RGB-LED-Light/1181359569.html
And some of these for periodic power injection. I plan to make my own T connectors like the ones that Cool Neon sells.
http://www.aliexpress.com/item/Free-shipping-30-Pairs-Power-Jack-Plug-2pin-JST-Connector-Waterproof-Cable-Wire-5050-3528-LED/1250851031.html
I’ve been using solderless connectors for prototyping at home but I wouldn’t trust them for the wearable projects I’m making. I always solder JST connectors to those. I couldn’t find 3 pin solderless connectors on aliexpress so I got them on alibaba: http://visionled.en.alibaba.com/product/750652216-213902928/3_wire_solderless_led_connector_for_led_strips_WW_CW.html
(Note that you can find various 4 pin solderless connectors on aliexpress)
Also re: injecting power I usually do that every 120-150 LEDs. The exact distance will depend on how many LEDs/m. I simply run speaker wire (+5V and GND) alongside the LED strip and solder it directly to the strip. When I experimented with 60/m strips it wasn’t enough to connect power on both sides of the 5m strip and I had to solder the power mid strip
Goddamn, I’ve been waiting for ages for solderless connectors like those to become available!