"Biblical Archeology Review"  Vol. 32: 2, March/April 2006, pp.7-8.
A letter  by Mr. Ralph D. Copeland from San Antonio, TX : he discusses this dagger from Ekron (around modern Gaza/Ashqelon). Ekron was one of the 5 Philistininan cities and the dagger in question likely dates to Samson/King Saul/King David period ( ~ 1000 BCE). It has an ivory (!) handle and is sharpened on the  concave side (as the author says" on the fingertip side in the photo" and may have a T-spine.
 His speculations: dagger? agricultural implement? ritual implement?
 His suggestion: it is rather a sickle than a fighting dagger, impossible to use as a cutting tool because of the location of the edge and the presence of a T-spine.
The  author of the original article, Mr.Seymour Gitin ("Excavating Ekron" BAR, Nov/Dec. 2005) apologized for the imprecision of calling it a dagger  (a weapon)and agrees that it is  likely to be a knife, ie a tool.
  My commentary: I could argue that there were multiple recurved swords and daggers all over the world, but I would rather get your opinion.
 Overall, the folks at the BAR could benefit from your experience.
their site: 
www.biblicalarcheology.org
e-mail address: 
bas@bib-arch.org