Thanks for your suggestions. Warning : This is a long-winded post about memberlists and profiles and has nothing to do with gardening!
When the forums were only a few months old we had a 'members list' option. After noticing some suspicious behaviour I ran a test and setup a user with a brand new email address :
'daffodils@mooseyscountrygarden.com' that had never been used before. I didn't publish this address anywhere. Within 3 weeks I'd received a spam email.
Someone was 'cherry picking' the moosey forums for email addresses to send spam to. After another month the forums started attracting attention from URL spammers - people who would register multiple times and fill the forums with ads for products, services and adult content.
So... I stopped the email addresses and homepage URLS from being displayed and removed the profile links to discourage the spammers and so far, cross fingers, it seems to have worked albeit at the expense of membership lists and profiles
Now I'm thinking a compromise is called for - how about...
1. I add profile links to the author of each post. These will only be displayed when you are LOGGED IN. Guests who are browsing the forums without logging in won't see the profiles. The search engines wont see the profile links either.
Throughout the forums I need to restrict the display of your email addresses and website URLS.
2. I'll make your profile homepages visible only to logged in users. If the search engines can't see homepage URLS this should deter spammers from signing up. Email addresses are going to be a bit trickier - If I allow guests to see your email addresses you WILL receive spam.
If I allow all members to see other members email addresses the spammers will register, login, then 'cherry pick' all of your email addresses, then send you rubbish emails.
I need a way of separating the spammers from legitimate moosey forum members. Sooo...
3. I could allow users who had posted say... 20 or more posts to see the email addresses. When someone starts spamming I disable their account before it gets to 20 posts anyway.
This is a little elitist but it would open up the forums without attracting unwanted attention. Thoughts anyone?
Ditto 2)
) It makes sense - however: do we actually WANT to lose the public nature of our correspondence - or, conversely, do we want to encourage private one-on-ones 
I for one would like people to eavesdrop on the worthwhile - that is how one builds new contacts and meets interesting new people. On the other hand (I'm a Libra) ideally you meet people with whom you wish to persue certain more technical discussions and even info that could just clog up the webpage - so the twenty-post-option is an interesting one.
