Number strings as search phrases?

No idea what these are...

[akmac]

Yesterday, the keyphrase "881478737567" was used 117 times to find my site-or so my logs say. What is this?

[fiestagirl]

I believe that would be people looking in the msn cache.

Something like this:
http: //cc.msnscache.com/cache.aspx?q=#####