banana when my DD was born other half and I weren't together. I really didn't mind what surname she had, as mine is really common (boring) and his is slightly less common. But a friend said it would make sense for her to have mine, in case I met someone else in the future and then there's be 3 surnames in the household (seemed as logical a reason for a decision as any). I gave her his surname as a 2nd middle name and mine as her surname.
Anyhoo, now we're back together and expecting #2, other half asked if #2 could have his surname (apparently it has always niggled that DD doesn't have his name - might have helped if he mentioned that 4 years ago!!!). I said there was no way I was having 2 children with different surnames, so we've just gone through the very easy process of changing her name, swapping the last 2 around, i.e. my surname is now 2nd middle name, his is surname.
So there's one option for how to use both names, and if you change your mind later, it's not hard to fix.
Oh and on the peanut thing, I recently heard something very interesting. The medical profession's relaxed attitude to peanuts is based upon the fact that in India peanut allergies are non-existent and, guess what, it's a staple part of the diet, and children are exposed to peanuts from the moment of conception.
I always figured it sounded dumb to say don't eat something in case it creates an allergy. Surely the more exposure you have the less likely an alllergy, or are we all trying to outsmart the BMA and WHO???