No approval. What to do?

Just a couple days ago I read a blog post about a student who had submitted an article manuscript without the permission of his/her advisor. (I wish I could give credit here, but I can't find the posting!) I was shocked when I read it. I couldn't believe a grad student would have the nerve to pull something like that. I do remember how frustrating it was when I had my first manuscript prepared and had to wait two months for one of the authors (incidentally, by advisor's father) to return the manuscript (by snail mail) with comments. Still, I understood that it was the proper thing to do. Anyway. This past Friday I was cleaning out my inbox and discovered that I had a poster abstract I'd been putting off due on Sunday (today). So, I put something together and emailed it to my advisor, who I then remembered was out of town delivering a guest lecture at another university. I had hoped he would see the email and give the abstract a few minutes of his time, maybe at his hotel in the evening, but I waited until 8:00pm this evening and no reply had come. So, I had to submit without his approval. I realize this is very different than submitting a manuscript without the approval of an author, but I still feel a little awkward about sending out an abstract with my advisor's name on it, knowing he hasn't even seen it. Hope he's ok with it when I see him tomorrow. (I should have with me some great samples I finished making this weekend. Hopefully that will appease him if he's upset!)