I've done a few long-termish mostly solo trips now, and you hear about communities like CouchsurfingCouchSurfing and Warm Showers (for cyclists). However I also really enjoy staying in hostels. Oddly, there aren't really forum communities on the hostel sites.
It's really quite disappointing when you reach a new hostel only to find it almost empty, when there's a busy fun one down the road.
Are there online resources or communities to find who is going to be at hostel X on a certain date, so you can try and meet up with other travellers?