When I dated, I would let the guy pick up the first check if I knew I'd be going out with him again and if he insisted. I knew I'd have an opportunity to reciprocate and take HIM out somewhere on a second date at least. If I knew it was a one-date only thing, I'd pay half or the full check just to get out of there and not feel guilty about having "taken advantage of him." I always had a credit card with me and enough cash to pay my share (and for a cab ride back home).
The one time I wish I had stuck the guy with a check? A guy asked me out for dinner at an expensive sushi place and said he wanted to take me there and that I'd love it. I love sushi and figured it'd be worth the money. (And I knew going in that I'd be paying my own share 'cause I never like to stick a guy with a check that expensive on what might be a one-date only thing.) When the check came, he sat there and made no motion for his wallet--even though he saw me getting mine out. I was about to say how much we each owed... He actually put his hand over my hand and said to me, "Oh, you're so sweet. Thanks for treating." I just paid. I figured I'd get a lot of mileage telling that story to all my friends. And I did. But now, I kind of wish I had excused myself to go to the restroom and just never come back.