Version 5 supports custom html allowing this to be on the client see:
KeithK's blog articlewell, printing numbers on the pushpin for example can be done if you create an .aspx page that doesnt deliver html content, but the pushpin image with a number on it.
Example:
we name our page Pushpin.aspx
we call it via pushpin.aspx?Number=<your number goes here>
in the page code, you do following:
FileStream stream = new FileStream("pushpin.gif");
Image img = Image.FromStream(stream);
stream.Close();
Graphics g = Graphics.FromImage(img);
g.DrawString(Request.QueryString["Number"],new Font("Arial",10), Brushes.Black, new PointF(0,0));
g.Dispose();
Response.ContentType = "image/gif";
img.Save(Response.OutputStream, System.Drawing.Imaging.ImageFormat.Gif);
thats it, now your pushpin.aspx doesnt spit out html content but your custom pushpin image.
••• Using a custom IHttpHandler .ashx is more efficient than using an aspx since the Page Handler has a lot of infrastructure and code that is totally unused in this case. You can pretty much take the code above and put it in ProcessRequest method of an IHttpHandler class.