For some time, GoogleTouring has let you upload KML/KMZ files containing placemarks into Google Maps with their In-browser KML view web app.
Now there’s a new app on the block: Jacob Reimer over on Reimers.dk has written an ASP.NET control that makes it easier to use Google Maps in ASP.NET projects, and he shows off what it can do on this map.
What he’s made is a kind of placemark authoring tool that easily lets you import from KLM/KMZ files, but export to KML and KMZ as well. For example, take this KML file [KML] of placemarks for Swedish universities. Click on it and it will load up in Google Earth. But if you right-click on it and save it to your desktop, then you can upload it to a Google Map and edit it. Register (for free), and you can upload your KML files to a file manager, so that you can access them from anywhere later or view them on a Google Map (with a permalink you can send via email). This is great for making Google Earth placemarks accessible to those who can’t use the app for some reason.
(A weighty aside: Are we really meant to call Google’s mapping service “Google Local”? In my use of it, the maps are almost never local — neither in the sense of being of places nearby nor zoomed in all the way. At least I don’t have to call it Live Local, which is double untrue, that.)