It really, really depends on what size of breast we're talking about here. There is no way in hell I could use those tape-on bra things, and I'm a 42DDD. My girlfriend is a 38D, and *maybe* she could pull it off. Maybe. And if you're looking for support, you're screwed. In reality, if you're looking for the support that a traditional bra offers, without the basic structure of a traditional bra, you're going to have a very hard time finding it. I've seen good things done with duct tape, though, which I have personally used, and know a lot of models who use it. You have to be careful with the adhesive, as many people have a sensitivity to it, including me, which is why I don't use it anymore.

I second the notion of the strapless backless bras. You get a lot of support, surprisingly enough, plus you have the advantages of being able to wear a deep neckline and deep back, with no straps. They take a bit of getting used to, though, because they're strangely uncomfortable. You do have to deal with the weird roll over at the bottom, both in the front and the back. Another alternative might be a backless or low-back corset--a real one, not a piece of lingerie. They're a bit harder to find, and they're pricey, but it would be an investment, and it would do *exactly* what you're looking for. One place to check out is timelesstrends.com. They offer low back underbust corsets, at one of the most reasonable prices I've ever seen.

Good luck. When you find something that works for you, PLEASE post it here! I'm also a large-busted woman, and there are a lot of pieces of clothing I simply can't wear, because I refuse to go without support, and I refuse to have my breasts hanging around my belly button. I feel unattractive, saggy, and frankly, for me, having it all hang out is simply physically uncomfortable. YMMV. I'd love to find a solution that doesn't involve a terrible adhesive reaction or feeling unsexy.

I would suggest those bras that you can change the strap lines on. Some of them have like 32 different ways to change them. Or they come with clear straps!!

Have yet to find a strapless bra, or "stickers" that actually support.