Why does Gandalf have the third elf ring?

[Osse]

In reply to an above post, if I remember correctly, Cirdan had correspondance with both Ulmo and Osse... two of the most sympathetic and involved Ainur towards those who still dwelt in ME... it's therefore not inconseivable that Cirdan had at least some information about the coming Istari. Good point about the Three possibly having 'minds' or 'wills' of their own, perhaps Narya itself spurred Cirdan's desire to give the ring to Olorin.
Also... what about the two stones of the White Towers (the Tower Hills stones) Their fate was never clearly put out... is it possible Cirdan made use of them to survey the sea (as that is the only view that they share) and thus gained knowledge of the Istari's coming. Were the Istari clad in the bodies of old men before or after arrival at the Havens... were they sent out already in their wizend raiment? Cirdan possessed fantastic foresight and insight into the minds of others, he could recognize true power when he sees it; rather than that of Saruman-self righteousness and the spell of his voice... seeming powerful but not truly as powerful (or incapable of actually USING that power in his state of mind) as he seems. Cirdan is an intriguing character that I wish tolkien had written more upon. Who knows what really spurred him to present Gandalf with Narya?

PS: the information concerning the other two of the istari (Alatar and Pallando) is available in Unfinished Tales... also you may find something here: Encyclopedia of Arda- under Istari