I'd really like a seamless service of the Canadian topo maps, similar to ArcGIS Online USA Topographic Maps, http://www.arcgis.com/home/item.html?id=4ee3622f0bfd41eea55ffa83aaf31a9f
If there is no service, is there a download site?
If the main Toporama WMS site is unavailable, www.AlaskaMapped.org has the seamless canadian 250k topos scanned from NTS paper maps under the BDL Extras service (also see here). In the online map browser it's called the SDMI.Topo layer.
Toporama is is more up to date, has better resolution (1:50k) and let's you grab/leave-out certain layers while Alaska Mapped has better performance (and Arcgis layers if you want them).
The FTP site is (much faster to get the data downloaded)
To see them on Google Maps (copy and paste long url)
ArcGIS.com has the Canada Topo Map service which mashes together data from a number of sources -- from Canvec (which drives the already mentioned Toporama) to the deprecated National Topographic Database to TeleAtlas. The result is a bit disjointed and often inaccurate, at least in the areas that I'm familiar with, but might be okay for your purposes.
Here is a download site for Canadian digital topo maps.
Actually after digging around a little more, this may be closer to what you are looking for. http://geogratis.gc.ca/geogratis/en/service/toporama.html
Is this what you are looking for, download wise? They are collared still though.