Which services could be used for personal notes ? Hi Philippec. Thanks for your question. I think you may be asking me this because I've commented on an Openstreetmap note which had been used for the purposes of providing a personal marker as described here: Notes#Use_of_notes_for_adding_a_marker_for_personal_use. There are all sorts of ways to make a marker for personal (or business) use. Some of these are very simple and some very complex. I'm going to guess that the only people who will find their way to this description are those looking for the very simple answers.
Here's the simplest of the simple ways to get a personal marker (if you prefer pictures look at this similar explanation): Go to openstreetmap.org (which is only one service of hundreds based on Openstreetmap data by the way). Look for the 'share' button on the right of the map (like a box with an arrow out of it). Click this. Check the 'include marker' box. Move the marker to where you want it. Copy the link text which has appeared. When you want someone to see the map you see simply send them this link text - the same way you'd share any other website address. If they click it they will see the same marker and map you were seeing.