The discussions of crossing the US/Canada border have been interesting.
Only once have I crossed with classic computer gear (I took a
SPARCstation 20 to Idaho Falls, Idaho for a list member, while en route
to San Diego from Saskatchewan) and I had no trouble at all at the
border. Then again, the story that I was delivering an old computer
with near-zero value to someone who wanted it for hobby purposes when I
was already driving that way did make sense. :)
I cross the border south of where I live (Regway, SK/Raymond, MT) about
once a month because I have a PO box in Raymond, MT. I sometimes mail
stuff from Montana. It's all non-commercial. I declare it, I often get
asked follow-up questions (which I answer sincerely) and so far, I've
always been allowed to enter. Coming back, I import whatever I had
shipped to the PO box (and anything I liberated from the bigger town a
few miles south) and declare it. Again, no problems. It's a 24/7
crossing but it's probably the quietest 24/7 one on the border.
Last Tuesday I brought my mail up at Pembina, ND/Emerson, MB because we
got the mail en route to Fargo and then went to Winnipeg. I declared
like I always do, and had no problems like I always do.
If I were taking really big stuff across I'd just be sure to print lots
of emails documenting the exchange, and make sure I had phone numbers
for the key people involved in case customs officers had questions.
Generally if you can show them that you're not doing anything for
commercial purposes (including resale), you'll be fine. Commercial
stuff can be done too but it requires some hoop-jumping and I haven't
learned how to do this since I don't have any commercial activities that
cross the border.
Jim