Calling yourself "san"

[pohnpei]

So 1,000 years (okay, it was only 25) ago when I took Japanese in HS and college, I was told that you can never call yourself "san."
But I have a friend who always calls herself that on the phone. "Moshi moshi... Eiko-san desu." Every time she says this I wonder... (I live in the US and don't have many native Japanese friends so I don't know what others say.)
Does anyone know if this rule no longer applies?

[fredma]

Hmm... That is weird. I have heard someone call themselves -san in an anime before, but that kind of shows the arrogance and ignorance of the child saying it.

I mean, the only thing wrong with calling yourself -san is basically you're being arrogant, and in a culture like Japan, being modest and humble is key.

I guess here in America, it wouldn't be as bad.

[Yamanchu]

Hi Pohnpei, yes, using san in reference is arrogant, and rather strange. I certainly wouldn't do it.

[Javizy]

san is an honorific suffix, in other words it's used to show respect. Showing respect to yourself is more stupid than arrogant... The only thing close to this you here is ore-sama, which is an over-the-top macho boastful way to say 'I/me'. I asked my (Japanese) friend what she thought, and she said it just sounds strange and wonders what kind of person your friend is... I think the lesson here is just not to use san after your own name

[Belton]

I can't remember hearing -san used referring to the speaker, but I have heard the diminutive -chan used in self reference. Since she is also using her given name rather than her family name, might you be mishearing san for chan?

What I have heard is the apparent use of an honorific referring to more senior member's of their family when speaking to someone I'd consider outside their group, when I would have though the humble form would be used.
tou-san rather than chichi and nee-san rather than ane.

All I can say is there is also often a mismatch between how a language comes to be spoken and how a language is described by grammarians. Languages change. You can't really say that a native Japanese doesn't know how to speak their own language. (I often dislike how some students speak English but I can't say it's not native speech. innit.
drifting off topic but there's a nice parody here)
But as someone learning the language it's best to stick to the established rules and the rule still is you don't use san in self reference.