[whpalmer4]

First, a bit of nit-picking: the links (and attachments) are synced everywhere, even if the recipient can't do anything useful with them. The sync database holds all of the data, regardless of the client's ability to utilize it, and this means that you can regenerate from any device if something goes bump in the night.

You can currently embed an OmniGraffle file (and I presume an OmniGraphSketcher file, but don't have the iPad app to test this presumption) in an OmniFocus document on the Mac, and when it is synced to your iPad, it will show up as an attachment to the action or project where you put it. You can then open it in OmniGraffle (or OGS) though you have to be careful if you are going to make changes — at the moment, you won't be able to send the changes back directly through OmniFocus. You also want to watch how many large files you attach or your database will get very large, leading to possible syncing slowdowns or even out-of-memory crashes.