First of all, why are you posting Notes 8 questions in the Notes 6/7 forum?
Secondly, you can generate a Notes URL in a computed field using the following code:
ReplicaID := @Left(@ReplicaID; 8) + @Right(@ReplicaID; 8);
" + ReplicaID + "/0/" + @Text(@DocumentUniqueID)
No idea how you'd drop that into an SMS, but if the users have smart phones, then surely you can send them E-mails?
(NB - this is from a Notes 6 database.)