here is my 2 cents.

for bug tracking i just use a google-doc spreadsheet, i can invite anyone i want to to edit or view it. its free so not much of an investment. i keep track of all tasks on there to just bugs.

i also run SVN on my web-host which doesn't add any additional cost to web hosting.

some clients have required the use of unfuddle or other such project management / bug-tracking software but i would prefer the free solutions i mention above.