$myText = (string)$myVar;
There are more details for string casting and conversion in the Strings section of the PHP manual, including special handling for booleans and nulls.
The casts allowed are:
- (int), (integer) – cast to integer
- (bool), (boolean) – cast to boolean
- (float), (double), (real) – cast to float
- (string) – cast to string
- (array) – cast to array
- (object) – cast to object
- (unset) – cast to NULL (PHP 5)
Source
http://us3.php.net/manual/en/language.types.type-juggling.php