Of course it is possible! You can put one (or more) gift idea (s) and everyone can Participate. You can choose to let your friends and relative participate for the amount of their choice or divide the entire amount in equal parts of 10, 15, 20... euros. 

Example (for a birthday gift): You communicate the address of the registry to the participants. They will be able to participate to the gift (ex: via bank transfer or online payment) and indicate a message. You get all these messages that you put in an envelope to be offered on the day of the birthday. Very easy !