What type of situation do you want your babe to share?  Is it at home with siblings or with friends who visit?  We've discovered that if friends are coming over, we begin by removing the toys that cause big problems of fighting etc...  plus we also ask my son before his friends come over if there are any "special" toys that he would like to put away for safe keeping.  We like to give him some ownership over the situation.  I agree that we often ask kids to do what we don't do ourselves.  We also just try to make it clear to everyone (the kids) that we will take turns to reassure them that they'll get their turn.  if a fight errupts over something we remove that toy all together.  I think that helps them realize that fighting over something doesn't work out in the end and that they need to find a better way to settle it.  If it's sharing with a sibling, we just have the rule that whoever has it at the moment is entitled to play with it as long as they like and only after they put it down then the other child can take their turn.  If my younger child is narrowing in on my older childs space we suggest that perhaps instead of getting into a flap about it, that my son help redirect her to a toy of her own that she may enjoy playing with.  I hope that maybe some of this helps, I'll be rechecking this question for more helpful answers myself. 

I came from Israel, and in hebrew we don't say "share" to kids. instead we incourage them to "play together". I continued that with my son, even though we're in Australia and everyone wants him to "share" - i kept using the "play together".

I'm basically against the "sharing" idea, because we teach them to "share" things, and we, as adults, give them the opposite example - when i come to your home, would you share your clothes with me, or your car, or your DVD player and so on? we adults don't "share" our "toys" with others. at the most we lend them or we let you have it for a while or we "play" together (watch DVD together).

I usually tell kids to play together and if they want to have something just for themselves - 5 minutes child A and then 5 minutes child B (of course 5 minutes or 10 minutes doesn't really matter).

Also, i'm not sure your child's age, but basically up until the age of 3 - children don't understand the meanind of "sharing" or "playing together" - so there's not much point of pushing them to do so. Instead try to have few alternatives when there are few kids around.

Hope that helped.

With the kids at the small day care I work for, I play change....    I explain that this is a fun game what we do is one person plays with this toy and the other person plays with that toy.. When I yell change you swap toys...

This has worked wonders for the kids and some times I forget to yell change I find they do it themselves..  I don't think they have much concept of time as some times it could be seconds for them when they are yelling it out for themselves, but they are so happy to play change...  

I hope this helps...