Applications of 3-collisions I recently read Improved Generic Algorithms for 3-Collisions by Joux and Lucks (Asiacrypt 2009), available as http://eprint.iacr.org/2009/305.pdf. I was wondering about applications of this technique (excluding of course the applications already given in appendix).
So my question is: Are there interesting applications (constructive or cryptanalytic, preferably practical) of this method that have been proposed since 2009 ?
There are more recent papers that cite Joux and Lucks.  Example: "Preimage Attacks against PKC98-Hash and HAS-V", Sasaki et al., uses the Joux-Lucks algorithm to attack two hash functions.

Have you looked at newer papers that cite Joux and Lucks?  Have you done a literature search, to find newer papers that cite their Asiacrypt 2009 paper?  Google Scholar, Citeseer, and Microsoft Academic Search can help you here.  That'd be a good start.  If someone uses the Joux-Lucks algorithm in their work, they'll probably cite the Joux and Lucks paper.