For those of you whose HP-01 pens don't write anymore:
go to http://www.garlandpen.com
tab to 'company store'
download order form (.pdf)
You can order one or more refill #125 (for dual pens) in medium blue only. Their service is very good, I got mine in about two weeks.
Thought I'd pass this tip along, some folks might not know it.
<<Al Schwarz>>