I'm running InvestingPit - Forex Spot & CME Futures Options Analysis Blog at https://investingpit.com/blog
I also have a thread on this forum in Analyst Arena at
http://forums.babypips.com/the-analyst-arena/79462-forex-spot-cme-futures-options-analysis-investingpit.html
Having a blog can be a good way to keep things archived and be more disciplined plus a form of storing everything investing related in one place.
Comments section below each blog post is also a good way to leave your own comment to gather thoughts.
All in all having a blog can be like a trade journal that everybody can have access to online.
Another plus site is that you can run a blog for free so it doesn't cost you anything but boost your self discipline.