I wrote a tiny command line application that will show content types for a specific web. 

Usage: ShowContentTypes <url>

Must be executed in the server. It uses the object model directly.

Get it here, download source here

Code below:

static void Main(string[] args)
{
if (args.Length != 1)
{
Console.WriteLine("Usage: ShowContentTypes <url> ");
return;
}
string url = args[0];
System.Console.WriteLine("Starting show content type for Url:" + url);
SPSite site = new SPSite(url);
SPWeb web = site.OpenWeb();
int idx = 0;
foreach (SPContentType type in web.ContentTypes)
{
Console.WriteLine(String.Format("{0} - {1}", idx, type.Name));
idx++;
}
System.Console.WriteLine("Ending");
}