-->See also: How to boost netbook performance
In the early time of netbooks you could find a lot of SSD as unique netbook storage type, one of the main reason for very poor performance of the early netbooks/EEE PC. Nowadays most of the netbooks are equipped with 2,5-inch hard disks, giving you much more space and more performance.
--> See also Netbook database
SSD (Solid State Disks) don't necessarily mean "low performance", actually there are SSDs that got much higher performance than traditional hard drives (see below).
Be careful if you want to replace your netbook hard disk with a SSD: high performacen SSDs are currently very expensive (e.g. more than 400 USD for 32GB) and cheap SSD got often bad write performance and/or high power consumption.
The two best SSD out there are Intel X-25 E and however are very costly and even not easy to get.
Solidata K6 seems to be very promising (32GB, about 140 USD) , at least from the datasheet: sequential read 200MB/sec, sequential write 160MB/sec. Power consumption: 0.3 W idle, Max 2W. I'll keep you updated...
SSD vs HDD
The SSD promise superior performance and lower power consumption. Big advantage for the SSDs is the absence of parts in movement: while performance of traditional hard drives are strictly related to disc spin speed, data density and physical position of the data speed. SSD performance are mainly limited by used flash technology and interface controller. On the other hand these SSDs are actually very costly (more than $400 for 32GB). In any case I bet that SSDs are going to completely replace HDD (Hard Disk Drives) whithin four to five years. Just the time to get high performance SSDs below the 100 USD mark...
Interesting article from tomshardware on SSD vs HDD
Some data on SSD vs HDD performance
Let's compare best in class SDD Intel X-25 E and vs best in class 3,5-inch desktop hard disks Wester Digital VelociRaptor VR150 and Seagate Barracuda 7200.12, data from actual tomshardware charts
Max read throughput: SSD 207-220MB/sec vs 121-131MB/sec for the HDDs
Max read throughput: SSD 187-205MB/sec vs 121-131MB/sec for the HDDs
Read access time: SDD 0.1 ms vs 7-10 ms for the HDD, it means that factor 70-100x improvement!!!
Source: tomshardware storage charts
--> See also: How to boost netbook performance
A few SSDs from Amazon: