R help - Nov 2010 - boxplot of timeseries with different lengths

Hello List,

I have a time serie of observations representing the activity of some users in
different time periods, like:
> table(obs1)
 user1  user2  user3 user31 user33  user4  user5  user6  user7  user8 user82
user83 user85   user9
     1      1      	3      	1      	1	  1      	6      	1      1      	1      	6
1      	1 	   7
> table(obs2)
 user1  user2  user3 user31 user33  user4  user5  user6  user7  user8 user82
user83 user84  user85 user86 user87  user9
     3       9         29      12          13          14        21        13   
13       15       20         21          1           11          9           4  
27

I would like to boxplot them, but since they have different length, I don't
know how to handle the dataset properly. Is it wise to use different arrays, one
for each observation? or it is better to force the tabled observations to the
same length, in order to put them into a data frame?

thanks in advance for any advice.

best regards,
Simone Gabbriellini