Ok Im a newbie so hopefully this post wont be redundant and will help others needing to find some of the ingredients needed for fondant recipes etc.

Glycerin - I found pure glycerin (USP grade) in 2 places....Wal-Mart (in the pharmacy department)
and CVS in the skin care department. I think it was like $6 for a 6oz bottle @ each. I think one of the reasons people have such a hard time finding it is because they dont stock it near the cake or cake decorating supplies. Dont expect any of the employees to know where it is, you just have to look.

Meringe Powder - You can buy meringue powder in the cake decorating section of the craft department at Wal Mart where the fondant etc is located (not in the cake aisle), I have also seen a product called "Just Whites" (same thing - powdered egg whites) at my local Publix and Ive heard Kroger carries them too. If you live near a Publix that doesnt carry it, just ask a manager to order it for you. Ive done this with several items over the years and Ive never had a problem. Also dont forget that Publix honors competitors coupons and even though Ive never seen a "just whites" coupon, they will honor a $5 off of $25 coupon from say Winn Dixie or another store so it might be good to stock up and take advantage of this to offset the cost of more expensive ingredients.

Dream Whip - WalMart located next to the Jello. Dont forget to get your Knox unflavored gelatin while youre there lol.

Hope this saves someone running all over town looking for ingredients!

Glycerin is found at Michaels too, in the Wilton section - along with meringue powder.

I know this is an older post, but I thought I'd let you know my tricks. I don't even use glycerin or meringue powder anymore..

You can always substitute glycerin with light corn syrup. It's close enough. Glycerin is used as a laxative actually, which is why you found it in the pharmacy section, my grandmothers actually swear by putting a lil corn syrup in the baby's bottle to help with constipation too lol.

As for meringue powder, almost any recipe you would need meringue powder for, you can usually tweak to include a cooked egg white mixture. I've actually been making royal icing this way for a lil while. I make a chocolate royal icing whenever I need a dark color... It is awesome. Just sub out some p.sugar for cocoa powder... Amazing!

What can I say I'm cheap and it always seems like I'm doing cakes in the middle of the night when i cant gonto the store so I've learned more than a few substitutions.

Glycerin is cheapest at the health food store. I buy a 16 oz bottle for about $8.

Just whites doesn't seem to be a substitute for meringue powder...it's stinky and if you read the meringue powder can, there are other ingredients in meringue powder, not just dried egg white.

Texas, I agree with you about the meringue powder. I hate using that stuff (the Wilton brand anyway). To me it has a very sour taste.