There are a variety of sites you can use to get price alerts for brick and mortar stores, online stores, and sites geared specifically toward online shopping behemoth Amazon. But what if you want to go to one place to compare prices, and get alerts when there's a change in price?

Depending on your needs, there's a variety of sites out there worth checking out.

Largest Selection

With NexTag, you can search for any given product, compare prices, and if you're not ready to take the plunge yet, set a price alert to find out when it goes down. NexTag includes results from Amazon, eBay, Newegg, and Overstock, as well as US retailers like Walmart and JC Penney.

Nextag

For the lesser known sites, you can read reviews by other NexTag users to decide whether or not to purchase the item from that store. To set a price alert for all retailers, click on the "compare at X sellers" link underneath the price, and then click the 'Set price alert' link.

You can then enter the amount at which you want to be alerted. (Price alerts can be set only for items available from more than one seller.)

Amazon Only

If you're only concern is Amazon, check out CamelCamelCamel. The website offers alerts for the various Amazon localized websites in the US, Canada, China, France, Germany, Italy, Japan, Spain, and the United Kingdom. The site also has a Top Drops tab, which shows you which items you can get with a serious discount.

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To set a price alert, search for the product, and you can choose an email or Twitter alert on Amazon or third-party buyer prices.

Works in the Background

Invisible Hand is a solid choice for anyone based in the US, the UK, or Germany, and works in a slightly different way. The service is available as a Chrome, Safari, and Firefox extension, and quietly works in the background.

When you look up an item on your preferred website, it will tell you if it's available for less elsewhere, but won't send out actual alerts. If you're looking at the lowest price, it will show you the next lowest available price.

InvisibleHand

The site boasts 54 US retailers, 44 UK retailers, and 20 German retailers, in addition to hundreds of airlines, but won't provide prices for Amazon.

Do you have any tips and tricks on how to get price alerts? Let us know in the comments.