Clustering partition and memory

Dear R-help list members

i would like to use R to produce clustering or partitioning of a dataset.
I am trying to use the functions:
- hierclust() of the package multiv
-pam(), agnes() and fanny() of the package cluster

But I cannot get any result because of lack of memory. Would you know any 
clustering function not to greedy in memory?
I have tried to expand my memory limit with memory.limit() but no 
significant results.

Thank you for any answer that could help.
Vincent