I'm not a full time coder, but I guess your problem extends to most heavy knowledge workers (like me).
As for contexts, I did come up with something that works great for me. The key is considering contexts not only physical tools and places, but workspaces with specific conditions and even mind states.
So I have my "traditional" contexts:
@mang - beach house
@lc - office of an organization I belong to
@ufes - university
@err - errands
And my knowledge work specific contexts (deliberately preceed by two '@' as to separate them in the tagcloud):
@@data - work requiring access to my personal/work data, such as project support material, work in progress files, reference file, and so on. Mindless computer work might go in here depending on it, and data entry always does.
@@fresh - a great work environment in a great mind state. I've got access to web, data and office supplies, and I'm fresh and creative. Usually morning work, tackling big tasks that require lots of thinking first thing in the day.
@@think - decisions and things I've gotta sleep on. I'll sometimes transcribe one or two of them to my on-the-fly pad so I can think about it on my commute or in some time window.
@@web - mostly mindless work with an internet connection. The mindful go in 'fresh', wich normally assumes web access.
You can see that three out of four of the @@contexts take access to a computer for granted.
As to cutting down the number of apps, I've tried using RTM for mostly everything, but came to the conclusion it's just not worth it. It bothers more than it eases, which go against the premise.
I'm now happy using different apps for various things, RTM being only for projects and next actions. Calendared stuff go on a shared calendar, like yours, and even goals (wich I tried to extensively implement in RTM, for their deep integration with projects) are now managed somewhere else (OOffice Draw). Nevertheless, I think projects and next actions are, if not the bulk of our work, the most meaningful part of it, and I consider RTM one of my best suited and most important management tools, especially in bringing awareness in weekly reviews and plannings.
Posted 5 years ago