We use SM for this.  We don't attempt to get the same type of "job costing" but for keeping track of these types of requests and getting them billed out it works pretty well.  It was a module that was added in by aquisition, so the integration with other modules is there, although it could be better.  It may be worth a look, though.

Thanks so much!  

We use extras for this.  We have a main job set up and hundreds of extras under the main number.  Example:  1-0025 NC Service jobs (main job) 44412 John Doe (extra).  We also use Excel spreadsheet to cross reference all the extra numbers.

I agree with two methods suggested, SM Work Orders/Small Jobs and/or Extras.  The two perspectives that might direct one method or the other is 1)  How do you bill these.  If TM, Works orders might be the easiest  IF lump sum, Extras with quick bill might be the easiest  2)  What level of cost management is required.  The more cost management (Cost Code granularity, the use of Extras/cost codes, but if you just need basic labor, material equipment, then SM can accomplish nicely.