Running in the forest alone is scary.
There are several options for running on trails with others in Cape Town. I am not sure what is happening upcountry but things must be moving along similar lines. Here is a short background to each so that you can narrow it down for yourself.

CRAG (Cape Runners Against Gravity) is the oldest and only dedicated trail running group in Cape Town. They do a group run every Wed night in Cape Town and have just recently started a chapter in the Somerset West area. It is a very inclusive group run in that they wait for everybody to catch up and then carry on. There is a walking group which caters for those recovering from injury. A weekly newsletter with information on weekly runs and other events is sent out to the mailing list. Runs start from a different venue each week. There are occasional weekend outings. Definitely for those just getting into trail while there are also some speedsters who attend. Mail to subscribe (crag-subscribe@yahoogroups.com).

Tim Bellairs from VOB running club organises the trail runs for them. He sends out a few mails a week. They run on Saturday mornings and have started a Wed night run. I have not run with them on Wed night yet but they will almost definitely be faster than CRAG. Check out VOB trail runners.

Patrick Cox from Celtics running club organises a Thursday run (mostly in summer). They have three different groups for different abilities and speeds. Visit Celtics on the web or mail Patrick to be added to his list.

I would say that the most challenging option is the fast group on Thursdays. I don’t know about the VOB Wednesday group but suspect that they are slightly slower. The CRAG group is very sociable.
All the above groups are very friendly and are happy to include everybody.

Douglas Rossouw of Fish Hoek coordinates their trail runs. Mainly Sunday mornings and some events. Mail douglasr@iafrica.com or phone 082 418 5945 for their gatherings in the deep south.

Hope this helps you all.
Please let me know of any other groups and I will put up links