Here's my dilemma. I met a post-doc at a conference a while back, and told him about the project I was working on at the time, and he subsequently invited me to give a talk in a session at an upcoming (next week) conference. I accepted, since it was my first invitation to speak at a conference, and overall I was/am excited at this prospect, and at the prospect of collaborating with him in the future. However for various reasons (mostly time commitment on my part), this particular project - which is really a side-project to my main dissertation work - hasn't panned out like I hoped it would when I accepted the talk. Needless to say, I don't feel confident that my talk will make a good contribution to the session, since my results are very lack-luster and my expertise in other aspects isn't enough to make up for this. Since I'm a PhD student and this is a side project, I don't have old work to "fall back on" and my advisor is impartial.
So which is better: cancel the talk and apologize to the organizer profusely, perhaps suggesting a future collaboration, or suck it up and give a woefully under prepared talk, risking embarrassment to myself? I'm leaning towards cancelling, because I feel like a poor talk makes me look bad to everyone who listens, while cancelling only makes me look bad to the session organizer.