I recently had a programmer in for an interview, who listed Python, PHP, Rails and ASP as a few of their skills. In the interview however, they interviewee didn't enough know what control structures and basic logic were, they had only followed a few demo tutorials.

So my question is this: At which point can you add a technology to your resume accurately. Is it when you can demonstrate all basic concepts, write a useful program in it, or are just comfortable using it without having to refer to the documentation every 30 seconds.

I don't believe this is overly subjective, a baseline should easily be established based on feedback.

You should be able to defend/explain each and every word you put in your resume. Kind of like you dissertation/thesis. I have seen many candidates rejected with the reason "could not justify what he had put in his resume".

One approach is to follow Google's self questionnaire. Rate each skill on a scale of 10. That way we can project how relatively comfortable we are with various technologies. 


1 means you can read others code with plenty of googling.
5 maybe for implementing modules in the technology. Etc.  
8 for plenty of experience and comfortable with designing and implementing large projects in that technology.  
9 for architectural knowledge with moderate understanding of what's under the hood. 
10 means you have written a book on it or invented it. 


I have seen resumes which have bar graphs indicating relative proficiency in various technology.

Another option is to group skills as "strong understanding", "moderate proficiency" and "familiar with".

Edit:

I tried to put this as a comment, but didn't look due to lack of formatting.

For a reference, here is what Google defines the rates in their Self Evaluation


0 – You have no experience
1 to 3 – You are familiar with this
area but would not be comfortable
implementing anything in it.-
4 to 6 – You are confident in this
area and use it daily.-
7 – 9 You are extremely proficient to
expert and have deep technical
expertise in the subject and feel
comfortable designing any project in
it.-
10 – Reserved for those who are
recognized industry experts, either
you wrote a book in it or invented
it.

