I proposed this minimal one a while back referencing the relays and not the ostrich:

But now I think we have an opportunity to do something with the nostr addresses Pablo is working on. nostr:npub10000003zmk89narqpczy4ff6rnuht2wu05na7kpnh3mak7z2tqzsv8vwqk already pointed out that using an @ is too confusing.
I'm thinking something like:

And then use that (n) as a recognisable logo.
Not saying it has to be exactly that, but that's what I'm brainstorming on.