Need to create -5.5/+5.5 and 25.5VDC from 12VDC wall wart
As other stated, there are thousands of solutions out there.  You also do not mention how much current you require, so making the assumption here that yours is a relatively low current (circa 2A) requirement.

One such possibility is to use the LT1941 from Linear Technology. This is a triple monolithic switching regulator. To quote the data sheet:

"Two of the regulators are step-down converters with 3A and 2A power switches. The third regulator can be configured as a boost, inverter
or SEPIC converter and has a 1.5A power switch"

Here's the link for more info: LT1941 Triple Monolithic Switching Regulator.  On the down side, you really do need to prototype on PCB given the nature of the application and the relatively high switching frequency (1.1MHz).

Another possibility is the ti LM5001 regulator.  Here's a good design resource for using the LM5001 in different topologies.  You can use the LM5001 in a fly-back configuration to obtain your three desired.  More design resources can be found on both Linear Technologies and Texas Instruments sites.  As far as cost goes, the LM5001 is also slightly cheaper than the LT1941, but do consider that the LT1941 packs a lot more features on-chip.