For my daughter's 5th birthday we had a "Doctors & Nurses" party.  My daughter LOVES playing doctors with her soft toys, tells everyone she wants to be a surgeon when she's older and I work in a hospital so when thinking of a birthday theme we stumbled on to the Medical theme.  I made a gorgeous "Surgeon" costume for my daughter from fabric covered in surgical cats and dogs (very big hit!). We sent invitations asking her little friends to come dressed up as their favourite medical character and we had doctors, nurses, orderlies and patients (even one who'd had a baby AND had chicken pox!).  I had colouring pages for when the guests first arrived in a kids medical theme. We played pass the stethoscope (the child holding the stethoscope when the music stopped was out), stick the Band-Aid on the cut (instead on pin-the-tail), a treasure hunt for chocolate gold coins (because everyone knows doctors have lots of money) and in pass the parcel each child got novelty Band-Aids (sticking plasters) in their parcel. We had ECG placemats, lots of thematic food (red cordial was blood, rolled up fairy bread sandwiches were bandages, etc) and the birthday cake was "Barbie Sick In Bed Cake" - I covered a rectangular butter cake with butter cream, put a Barbie in pyjamas on the bed then covered her with a "sheet" made with rolled out soft icing (the type used to cover wedding cakes). I used melted white chocolate to make the ends of the bed, making frames the shape of an old-fashioned hospital bed which attached to the bed cake with a little melted chocolate when they were set.  (The cake was a HUGE hit with the kids and the other Mums - very easily made but looked very impressive). The biggest hit of the party were the loot bags - plastic vomit(emesis) bags (never-used!) - along with the normal lollies ,etc I put in theatre socks and masks, trauma dolls, patient stickers - the kids LOVED them, although the Mum's needed reassurance about the vomit bags! My daughter had a fabulous day - her 5th birthday will long be remembered. It was also great to have a party away from the obvious themes - lots of scope for new ideas!