How to tune vm to be less swap happy?

[Andrea Aime]

Hi everybody,
sorry to bother you with this question, but I feel that current vm defaults 
are not tuned for a workstation use, but for a file server/db server use.
I work on a couple of machines with 128MB of RAM, tipically use KDE 3.0
and Netbeans (a Java IDE). Ok, I use bloated software, I should have more
RAM. Fine. But what I don't understand is why the system keeps swapping
data in and out just because it doesn't want to shrink the cache below 40 MB.
My typical memory occupation is:

             total       used       free     shared    buffers     cached
Mem:        127096     123264       3832          0       1216      48164
-/+ buffers/cache:      73884      53212
Swap:       257000      62316     194684

Now, as you can see I would need 135 MB to keep all my programs in memory,
and if you look at top output:

 PID USER     PRI  NI  SIZE  RSS SHARE STAT %CPU %MEM   TIME COMMAND
 4397 wolf       9   0 79196  71M 30472 S     0,0 57,4   0:00 java
 4398 wolf       8   0 79196  71M 30472 S     0,0 57,4   0:00 java
...

you'll notice that due to the cache behaviour not even netbeans fits enterely 
in memory. I really doubt that I can benefit from a 48MB disk cache since the 
system is swapping in and out every time I open konqueror, kmail and the 
like... is there anything I can do to shrink the cache and to allow a bigger 
part of my working set to fit into memory? Moreover, what vm tuning do you
advice for a typical workstation use with memory hungry applications?
Best regards
Andrea Aime