[This post was originally written in June 2009 for my old blog, Lijiang Times.]
One of the common misconceptions about the Dongba script is that it’s not really a living, working writing system. Phish!
Whilst tactically avoiding instant inebriation at the hands of the Dongba priest He Xiudong’s self-brewed paint stripper (baijiu) one afternoon, I discovered his phonebook. Now, He Xiudong can’t write Chinese, so everything he notes down is in the Dongba script – including the phonebook. This means all the names are wrriten in Dongba, and Chinese names are transliterated phonetically. The phonebook is written on traditional Dongba paper.
Looking at the phonebook you can see that the most common family name is 
ho33 (Chinese 和 he), the Naxi character for which means ‘ribs’. Ho is a traditional Naxi family name (and incidentally the name of all the Dongbas at the Lijiang Dongba Culture Research Institute). Ten out of the twenty-two names listed on these two pages share this same surname.
Very interesting. Maybe this post and other related with the non religious phonetic use of the Dongba pictographs point out that this pictographic writing was developing to become a syllabic one. It is possible that this was the path followed by the Nuosu in the development of their writing system (http://www.ethnic-china.com/Yi/yiscript.htm). It is possible that parallelisms between the development of these two writing systems can help to understand what the Dongba script meant for the Naxi.
Hi Pedro, I’m not sure if it was becoming truly syllabic as such – I would perhaps suggest logographic with an exceedingly heavy reliance on the rebus principle to extend the set of 1,000 + logographs. In the newly-printed materials, such as textbooks, a logograph is used for every morpheme. The Yi script is something I know very little about: do they have an extant literature?