Just so it's clear; the VAX in the above picture is a vacuum.. and no.. it doesn't really run OpenBSD, a case of ironic brand naming.
With the size of x86 systems shrinking, you can actually find x86 based phones.. typically made overseas, and running Windows.
One product I'm aware of is ITG's "xpPhone", other similar products exist.. and it should theoretically be possible to boot BSD (..granted some hardware might be unsupported).