Just to throw in my own $0.02...
I also use the iPhone app purely as a "doing" and "collection" tool, rather than a planning tool. My MBP is normally with me anyway, and the planning is far better done on a real keyboard and screen (one of the rules for computing happiness: Never use a mobile device to do work that would better be done on a real keyboard, no matter
what that work is).
Collecting on the iPhone was a bit of a chore until a couple of updates ago due to the iPhone app's load times, but that's recently been fixed, and you can now hit the "Inbox" button and type something in while waiting for other stuff to load. I am a fan of the "collect-now-process-later" methodology, so when I'm on the go,
everything goes into the Inbox, and then gets reorganized and dealt with later during my weekly review.
The other method that I use for quick collection when I'm really busy on-the-go is Jott. While it's not a free service (anymore), it's a great way to dump things into my "Inbox" while I'm driving places, which is frequently when things occur to me. An Applescript and Mail.app rule collects these Jotted items and automatically dumps them into my OF inbox (courtesy of
http://www.leancrew.com/all-this/200...and-omnifocus/ ).
On the desktop, I use about 6 key perspectives that live in my toolbar: Review, Strategic, Tactical, Urgent, Flagged and Home. Review and Strategic are project-view perspectives, while Tactical is my "doing" perspective that shows only available actions in their appropriate contexts. Urgent and Flagged filter based on either overdue/due-soon items (urgent but not necessarily important), or flagged items (important but not necessarily urgent). Credit actually goes to Fraser Spiers for this particular layout, which he posted in his blog a few months ago.
Home is a special perspective that limits my focus to my "Personal" folder, since I work from home and therefore much of what lands in my "Office" and "Computer" contexts is a combination of both work and personal items. Naturally, on the weekends, I don't want to be thinking about doing work-related stuff, but home projects still need my attention.
Perspectives
are a missing component of the iPhone app that would certainly fit into the nice-to-have category, but thus far I've been mostly able to get by without them... The strategy for me has been exactly what others have suggested in terms of creating a more hierarchical context list so that I can easily group related contexts and drill up and down through them. For example, I had a top-level context called "Errands" and then sub-contexts for various specific locations, some of which are geotagged on the iPhone (another nice feature of the iPhone app). General errands go into the top-level context, while location-specific errands go into the appropriate location-based contexts.