One of the things I don't like about knitting garments seamlessly is the gaping maw of the reserved underarm stitches staring up at me like a big, sloppy chasm of despair.
It makes the piece hang strangely, even as I'm just knitting on it, and the whole stupid look of it fills me with ennui and makes me not want to work on the project. (Perhaps that's why TMW finished her Amelia before me... Yes. That must be it!)
So, whenever I'm in this situation, I soldier on through the first few inches, then graft the stitches as soon as I can. In this case, last night. I'm terrible at describing techniques ("you know, you just kind of do it,"), but there's a good description of grafting here.