If You want to tweak the system to use a less energy-consuming profile, that's a bit more manual work.
There is an application called Jupiter which has some nice feature possible to access from the GUI - but it maybe don't have the one-button-eco-mode feature that the Eco utility supports.
From the console you should be able to run powertop - a pretty cool program that enables you to set certain devices into a power-saving mode.
Find info about PowerTOP here: Link: http://www.lesswatts.org/projects/powertop/
For the more adventurous user there has been a lot of talk about the ASPM feature in Linux vs BIOS.
ASPM will save some power but is by default not enabled in recent kernels due issues with bad BIOS'es not reporting ASPM support in a proper way.
You may pass boot parameters to the kernel before booting and this is were You manually force ASPM support to be enabled.
The parameter you should use is this one:
You should realize though that if your BIOS is not supporting this feature, the unit may hang.
No big problem, just restart and do not pass the kernel parameter and the issue is gone.
If you notice your PC works well with the ASPM enabled, you should consider making the parameter a permanent setting. Depending on if you're using LILO, GRUB or GRUB2 the methods vary.
I have the pcie_aspm forced all the time and this works fine on my Toshiba's.
Thank you very much for your complete and informative answer, MannerhagenVPO. I'll give those a try once the warranty expires or i'm sure all the hardware is properly supported (whichever comes first).