To have "samples" of your skills that would be convenient to share consider public activities, like writing your blog, or answering Stack Exchange questions, or participating in open source projects.
what is the de-facto standard
Based on my experience (I've been at both sides of interview 20-30 times in 15-20 companies, along with few dozens times when I've been an interviewer myself) de-facto standard is not to show samples of your past work, neither on laptop, nor sent by mail, nor anyhow else.
This is a rule with exceptions: I've been asked about something like past work samples once or maybe twice.
The reason why it is so is I believe widespread understanding that this is legally slippery: past work may be owned by your past employer, or may be somehow else legally protected etc. It may be safe or not, depending on particular case but it's often too difficult to figure.
...is it ok to just talk technical about some of them?
Oh, be careful about "just talk technical". No, not in the sense that it's not OK - but in the sense that if you mention you know something, you better be prepared to answer questions proving your knowledge.
And, trust me, if you happen to get to an interviewer who is interested in skills / experience you mention and happens to know it, they will find a way to check your knowledge without any stinkin' samples.
I once skipped to specifically prepare to questions on a topic I bragged about in resume since I have a pretty good knowledge of it - you know, repeat basics, refresh fundamentals, stuff like that - what an epic fail it was when a qualified interviewer drilled into it.