I think it depends on your age!Exercise will help, and losing slowly so the skin can accomodate, but once you get past the menopause everything seems to be pleated! Massaging with cream may not do anything but it feels good!
I agree lose it slowly and it will reduce the amount of loose skin you'll be left with when you're finished. But remember the wonderful thing you'll be doing for your health too, you'll feel so much better and be able to do so much more! That makes up for the skin and if it really bothers you when you're done there is the surgery route. There will be a lot of people who will tell you this lotion or potion will sort it out but it wont, though keeping your skin moisturised and supple will help you feel better about it and as Judimac says it sure does feel good lol!
actually if you massage the skin quite vigeorously it DOES do something.. the act of stretching the skn triggers the production of collagen and can be used instead of surgery where the skin is only sagging a little .... exersize will help to tone up the muscles underneath whch will also improve the look.. start doing it now as you are losng the weight.. dont wait until you have lost the weight .. .. nothing is going to act as a miracle cure.. having had 2 kids that sent my belly to the size of a small house, i can vouch for that ... but you can make big improvements. Dont lay out for expensive creams etc.. bio-oil is about as far as I would recomend spending money wise, try and go for anything that has vitamin E in it, or cocoa butter .. both have got really good healing propoerties for scaring ( stretch marks) infact you can even buy the vit E capsules from the store and prick them with a pin and use the oil neat onto the skin.
Anyway, really hope a bit of that might help
failing that, you can do what I do .. i tell anyone who catches a glimpse of my tummy that ' it was badley burned in a fire ' lmao!!! :-D