Ecco and Pocket Informant
I am assuming that when you use PPC you are talking about a PocketPC... If that is the case, then I can tell you what I am doing.
I use Ecco Pro on the desktop. There are other posts here that can tell you the many benefits of using Ecco on the desktop. I then sync that information (via PDASync from Laplink) to my IPAQ. On the PPC, I am using Pocket Informant. With PI, you can filter by one or more categories. You can also save "views"; that is, once you get your @Home context set up (ie: Home and computer categories, only show items either due or starting today, order by priority etc) you can save that view and many other views. PI also lets you link information across tasks, calendar, notes, contacts etc. However, those links obviously will not show up on your desktop.
I think the solution depends on where you spend most of your time; if it is on your desktop (like I do) then Ecco is fantastic, and with the solution I have described above, I find I have enough information on my PPC to let me make the decisions I need to make when I only have it as my source.
--David