DiiGo annotations on TrailFire annotations are possible:
The author experienced this, when he made a DiiGo annotation on a the first TrailMark, starting from its TrailUrl.
You might want to [visit this TrailUrl] for experimenting with it.
- This looks like an interesting technique. I'll try to apply it after I return from my unexpected travels, the week after next. -- HansWobbe
Hans, thank you for your subtle hint on the Flickr page. Indeed, the flickr community practises consequently back linking. -- fridemar