Tonight, the 8th night of chanukah, is also know nas zos chanukah. From my daily halacha email:
The 8th day of Chanukah is known as “Zos Chanukah” (in earlier times it was called “Chanukas Hamiz’beach”) named for the Torah portion we read. The day is mesugal for one to daven for; barren women to have children, for a Refuah Sheleimah, and for one to be blessed with increased Parnassah.
You know what is the best segula? YOURSELF! Zos Chanukah has the Kedusha of the past 7 days of chanukah built up. The sefarim hakedoshim bring down how its a very mesugaldik time to daven your heart out infront of the candles. Your own words. It is especially true with zivigum. Daven for anything and everything you need.
The Bnei Yisschar brings down that for barren women it is a special time during Channuka and especially zos channuka (http://www.hebrewbooks.org/pdfpager.aspx?req=4683&st=&pgnum=120&hilite=). The Gemara in Shabbas(23B) itself brings down a segula of having children who are talmidim chachmim by lighting as Rashi brings down from Mishlei(6) ner mitzva v’Torah ohr,ner mitvah = Shabbas,and channuka = Torah ohr.