You can use VirtualDub.

nice recording quality, very
like this.
i think u should upload it to nico douga
u should turn the volume down for the song, i cant distinguish ur drum and the original song 
ultiman = me

stay tune for another shamless self ad guitarist and maybe pianist too

I use a combination of audio recording on Audacity, and video recording on my cellphone (LG Viewty). The video is transferred to a PC.

a) Download Virtualdub (it's free, google it)

b) If the video is in a format that is not in *.avi format, then use All2AVI software (also downloadable free from sourceforge) to convert to AVI, OR load the file in Virtualdub using a script called AVIsync

c) Load the video in Virtualdub, then at 'Audio' menu, choose "Audio from another file". Next is the tricky part. You will need to go to 'Audio', 'Interleaving' then at Audio skew correction, add (+xxxx) or subract (-xxxx) in milisecond the amount of time you need to offset to match the video. This takes trial and error.

d) Finally, before you 'Save as AVI', go to 'Video', 'compression' then select a suitable compression to save the AVI file as (otherwise the file will be uncompressed (GBs) and takes too long to upload to utube). I use ffdshow. If you do not have the codec on yer computer, install k-lite or cccp codec packs.