I'm also a sole founder. I don't feel _that_ disadvantaged because I have a mixed business/tech background, but in terms of applying to YC it's clear that being on your own is a major mark down.

It could be fairly interesting to see if a couple of technical people, working on different products, could act as one company. Both parties get the benefits of having someone to look over their shoulder (as they have a financial stake). You also get the sum of both sets of secondary skills and contacts. The downside would be a split in focus, but that should be no worse than the two working individually.