If it takes off it could be the biggest disruption yet to the current way of doing things, with new handsets and phone contract renewals becoming rarities.
Project Ara isn't commercially available yet, but the first handset is set to launch in January 2015 for just $50.
Oppo might not be a big name in the west, but in China it's a major player, albeit a relatively recent one, and it's likely to start making a dent in the US and Europe over the coming years too.
There's no one thing that Oppo is doing to stand out, but it's a company which isn't afraid to innovate. With the Oppo Find 7 it delivered the first 2K display on a smartphone, while the Oppo N1 has the option to run CyanogenMod and has a swivelling camera, so you can leverage its 13 megapixel lens for selfies and video calls.
Only the latter of those two phones is currently available in the UK though, carrying a price tag of roughly £390 (about US$661, AU$750).
Oppo might never be as big over here as Samsung or Apple but with a few more ideas like that it could certainly make a name for itself.
GeeksPhone is perhaps the least well known of all these, but that doesn't make it any less exciting or potentially disruptive.
It's a recent company focussed on building phones for open source operating systems and as part of that it's one of the handful of manufacturers currently supporting Firefox OS.
Its Revolution handset is one of the most powerful Firefox phones around so far in fact, though with a 1.6GHz dual-core Intel Atom processor, 1GB of RAM and a 4.7-inch qHD display it's still distinctly mid-range.
But it's got more than specs and a fledgling OS going for it, as it can also dual-boot Android, so users have a choice of two operating systems at any given time. The Revolution can be ordered now for €164.46 (about £135, US$229, AU$244) excluding taxes.
GeeksPhone is also involved in the making of Blackphone, a handset with top of the line security features.
Ultimately GeeksPhone is unlikely to rise to the top of the ranks, but it's providing some compelling if niche alternatives for people who want something a bit different.
- In fairness to Samsung, it sometimes thinks outside the box too.