I'm a die-hard user of Yojimbo, so when FileMaker announced Bento, I became both excited and worried. I'm excited because it could be better than Yojimbo. I'm worried because if it's better, I'll want to switch... and it may not have an easy import feature. :) I have a ton of information in Yojimbo, and I love that it syncs across my machines via .Mac. I keep lots of miscellaneous information in there like travel itineraries, product serial numbers, PDF manuals for cameras, and more. Spotlight indexing makes it really easy to find, even when Yojimbo is not open.
I'm going to try out Bento, too.