If you've just installed a bitcoin client it would take quite some time to catch up to the network. It has to download all transactions and build up an internal database, including doing some crypto work on the data.
The issue is exacerbated by fact that the client has to sync to disk very often, making the process IO bound.
It was taking me several days to go from 95% to 97% complete, which was quite frustrating.
Use a RAM disk. Create a partition of ~4Gb. Go to bitcoin folder in your profile
Copy the files from that folder to the RAM disk you've created and start the client with -datadir flag pointing to the RAM disk.
The performance of the local index build will be significantly increased.
Once you reach 100% sync - shut down the client. Copy the files back to the original folder and start client in a regular fashion.
TmpDisk software for Mac - http://tmpdisk.inkscribbles.com/
Use loopfs on linux
Windows - http://memory.dataram.com/products-and-services/software/ramdisk