Doing research is key here. Knowing your value in the current economy is the only wave to negotiate the salary you want and deserve. Once an offer has been made, your potential employer may pressure you to give an immediate yes or no on the offer. Resist it, and ask for at least a few days to mull the package over. If the number is low, prepare a counteroffer. Remember to consider perks as part of your package, especially if the employer won't budge on salary-vacation days, your own laptop and an assistant can turn a ho-hum offer into a compelling one.
When your iPod skips or your Wii remote starts acting funky, don't assume you'll have to cough up the cash to have either replaced (presuming you opted out of the extended warranty). If your problem has been a common complaint among users (the web has countless user review forums for popular gadgets), the manufacturer (and sometimes the retailer) may be willing to fix the problem for free. Press the issue. You won't get anything if you don't ask.