For example, say if a user wanted to 'add a place' to my database, how could I create a page almost instantly with that place's name in the domain e.g www.mydomain.com/placename?
I understand it might be a complex solution so if it is too complex to explain can you please push me into the right direction of what I should be researching.
If I understood you right that's one approach to what you want to do.
First of all try to understand mod rewrite. You could "mask: a GET url into a much nicer format.
Start here : http://www.elated.com/articles/mod-rewrite-tutorial-for-absolute-beginners/
Then google on and get yourself familiar with all the possibilities.
After that make sure the GET variable is unique in your database, to be absolutely sure use a unique ID.
Example :
domain.com/PLACEID/PLACENAME/
mod_rewrite could then translate this to your php script into :
domain.com/place.php?VAR=PLACEID&VAR2=PLACENAME
Search the data from the user/place through the PLACEID .
Good luck
I'm assuming you're using Apache. If so, create a rule using mod_rewrite that forwards requests for /place/placename
to /place.php?name=placename
. Then write the place.php script, which will pull the user page from the database and display it in the appropriate fashion.
That's one way to do it - there are others.