If this is DB2 UDB (Linux, Windows or Unix), you can have your DBA setup a Statement Event Monitor. This will capture all SQL and give the amount of time each took. However, this will not report LOCK-WAIT time which you are concerned with - and it will spew out tons of information and could easily consume all of your free disk space.
In order to determine what is causing the database contention, the best "free" tools available are the LIST APPLICATION SHOW DETAIL command to see which connections are in a LOCK-WAIT state and/or the GET SNAPSHOT FOR ALL APPLICATIONS which will show what each connection is doing and if they are in lock-wait, what are they waiting for and from who. Both of these commands will have to be run at regular intervals to generate the type of information needed to diagnose the problem. Start running every minute and run more often if necessary.
Both solutions will require that you turn on the MONITOR SWITCHES - I recommend turning on all of them to get the most information possible to diagnose this problem.
There are tools available - such as the ACTIVITY MONITOR which is part of the DB2 V9 client - that can help diagnose the issue. Other monitoring tools such as the Optim Performance Manager and Quest Spotlight which can be bought to help diagnose these types of problems.
Personally, I have a set of homegrown scripts that use the List Application and Get Snapshot infotrmation to monitor and diagnose these types of problems 24x7. They are not pretty (no GUI, just test) but they get the job done quickly and for free.
Greg