I have been having the exact same dilemma as you're experiencing. I'm now working out of my house, so my home and work are one and the same. The computer is always available, so that doesn't change.

Here's an idea that I've been playing with, that perhaps you could add to. Instead of separating tasks by location, how about less tangible aspects. For example, I have @Social context, for when I feel like talking to people. Some days, I truly never feel like having much of a conversation, but on the flip-side, once I start talking, I tend to get on a role. In this way, I'll make all 5 phone calls that need to be done all at once.

Another could be @mindless for tasks that require a bare minimum of brain function. As an example, right now I have about 9 months worth of personal financial records to correctly categorize and balance. When done 10 minutes at a time, its not too difficult. Luckily, it also doesn't require much thinking, so it can be done at 2am when I can't sleep. Compare this to another actual item on my lists which is "Make draft business card". The second needs to be done while alert and functioning. I personally have @low-concentration and @high-concentration, but since I find those names boring, I'll be changing them soon.

Another option that I have not tried but have seen tossed around is breaking down the list by anticipated time. Is it a 10 minute or 45 minute task?

Some food for thought, and I'd be very interested to hear further thoughts on the subject.