FileSystemWatcherToObservable

void Main()
{
	var fsw = new FileSystemWatcher(@"c:\"){
		IncludeSubdirectories = true
	};
	fsw.EnableRaisingEvents = true;
	var created = Observable.FromEventPattern<FileSystemEventHandler, FileSystemEventArgs>(h=>fsw.Created+=h,h=>fsw.Created-=h);
	var changed = Observable.FromEventPattern<FileSystemEventHandler, FileSystemEventArgs>(h=>fsw.Changed+=h,h=>fsw.Changed-=h);
	var deleted = Observable.FromEventPattern<FileSystemEventHandler, FileSystemEventArgs>(h=>fsw.Deleted+=h,h=>fsw.Deleted-=h);
	var renamed = Observable.FromEventPattern<RenamedEventHandler, FileSystemEventArgs>(h=>fsw.Renamed+=h,h=>fsw.Renamed-=h);
	
	created.Merge(changed)
		.Merge(deleted)
		.Merge(renamed)
		.Select(x=>x.EventArgs)
		.Select(x=>String.Format("{1} was {0}",x.ChangeType,x.FullPath))
		.DistinctUntilChanged()
		// use linqpad's utility observer
		.DumpLive();
}